So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued to
the rear hatch. I'm thinking that if it was removed a gasket could be
installed, and hinges, gas springs, and a latch installed. So can this
be done? Anyone here done this? I'm pretty sure that making the hinge
assembly, latches, and handle won't present any real challenges. After
all, I do have a complete mahine shop and I am a machinist.
Eric

wrote in message ...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued to
the rear hatch. I'm thinking that if it was removed a gasket could be
installed, and hinges, gas springs, and a latch installed. So can this
be done? Anyone here done this? I'm pretty sure that making the hinge
assembly, latches, and handle won't present any real challenges. After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

On Tue, 10 Sep 2013 17:11:53 -0700, wrote:

So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued to
the rear hatch. I'm thinking that if it was removed a gasket could be
installed, and hinges, gas springs, and a latch installed. So can this
be done? Anyone here done this? I'm pretty sure that making the hinge
assembly, latches, and handle won't present any real challenges. After
all, I do have a complete mahine shop and I am a machinist.
Eric

Well, rear view mirrors are often glued to the glass. They even make a
special glue for it - saw some in Home Pro. But I've also seen what I
assumed to be tempered glass windows with holes drilled in them.

Or, you could just make a new window from Plexiglas :-)

--
Cheers,

John B.

wrote:
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued to
the rear hatch. I'm thinking that if it was removed a gasket could be
installed, and hinges, gas springs, and a latch installed. So can this
be done? Anyone here done this? I'm pretty sure that making the hinge
assembly, latches, and handle won't present any real challenges. After
all, I do have a complete mahine shop and I am a machinist.
Eric

Not that difficult to glue metal to glass. Hit a glass shop and they
will sell you the supplies. It take an etchant on the glass and a
special adhesive.

However if that vehicle is like many of the newer ones that glass is
probably a structural part of the hatch. You may need to add some extra
metal to the frame of the hatch to make up for the lack of the glass.

Then you need to come up with a way to seal it when closed to keep
rain/air out.

--
Steve W.

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued
to
the rear hatch. I'm thinking that if it was removed a gasket could
be
installed, and hinges, gas springs, and a latch installed. So can
this
be done? Anyone here done this? I'm pretty sure that making the
hinge
assembly, latches, and handle won't present any real challenges.
After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

I can't reach in very far with only the upper glass open and usually
have to open the lower swinging door to reach anything that braking
has moved forward against the seat backs, or load groceries where they
won't tumble. You could tape some rope across the opening at sill
height to see how much useful access you would have.

This is the hatch arrangement. The folding table is the floor of the
rear compartment. I covered mine with plywood to support the weight of
machinery.
http://farm1.staticflickr.com/230/52...07c819cf_z.jpg
Later models made the glass part of the door, which is probably
better.

I installed the optional child restraint seat fittings in the roof
just in front of the hatch hinge and have used them to hold up a net
when I had a lot of loose gear piled in back, so it wouldn't spill out
when I opened the lower door. I would have added tie-downs on the
floor if it hadn't come with them.

The mirror glued to my truck's replacement windshield fell off when I
tried to adjust it, on the way to the state inspection. The outside
mirrors were enough to pass.

jsw

On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued
to
the rear hatch. I'm thinking that if it was removed a gasket could
be
installed, and hinges, gas springs, and a latch installed. So can
this
be done? Anyone here done this? I'm pretty sure that making the
hinge
assembly, latches, and handle won't present any real challenges.
After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

Glass is not among the materials I study much, but I suspect that, in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.

--
Ed Huntress


I can't reach in very far with only the upper glass open and usually
have to open the lower swinging door to reach anything that braking
has moved forward against the seat backs, or load groceries where they
won't tumble. You could tape some rope across the opening at sill
height to see how much useful access you would have.

This is the hatch arrangement. The folding table is the floor of the
rear compartment. I covered mine with plywood to support the weight of
machinery.
http://farm1.staticflickr.com/230/52...07c819cf_z.jpg
Later models made the glass part of the door, which is probably
better.

I installed the optional child restraint seat fittings in the roof
just in front of the hatch hinge and have used them to hold up a net
when I had a lot of loose gear piled in back, so it wouldn't spill out
when I opened the lower door. I would have added tie-downs on the
floor if it hadn't come with them.

The mirror glued to my truck's replacement windshield fell off when I
tried to adjust it, on the way to the state inspection. The outside
mirrors were enough to pass.

jsw

"Ed Huntress" wrote in message
...
On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just
glued
to
the rear hatch. I'm thinking that if it was removed a gasket
could
be
installed, and hinges, gas springs, and a latch installed. So can
this
be done? Anyone here done this? I'm pretty sure that making the
hinge
assembly, latches, and handle won't present any real challenges.
After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a
silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly
stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

That was purely a description, not a prescription. If you find an
instance of a high-stress glue attachment its repair procedure and
materials should be helpful.

Glass is not among the materials I study much, but I suspect that,
in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.

--
Ed Huntress

If the glue ages and fails, like my professionally installed mirror, a
sharp maneuver could fling the hatch glass into another car's
windshield.

jsw

Ed Huntress wrote:

On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued
to
the rear hatch. I'm thinking that if it was removed a gasket could
be
installed, and hinges, gas springs, and a latch installed. So can
this
be done? Anyone here done this? I'm pretty sure that making the
hinge
assembly, latches, and handle won't present any real challenges.
After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

Glass is not among the materials I study much, but I suspect that, in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.


The glue may need to be somewhat flexible to allow different rates of
expansion between the glass and the frame. Or arrange the frame to be made
in parts than can slip or flex slightly as the glass expands/contracts.

If the rear window is already held in with glue, just use the same stuff.
They've already solved that problem.

The other alternative is to make a frame with a flange that will mate with a
standard windshield rubber gasket. The glass sits in one slot in the
gasket, the frame in another. Turning the gasket around (frame on the
outside, glass toward the inside) might allow the face of the rubber gasket
to act as a weather seal against the car body.


--
Paul Hovnanian
------------------------------------------------------------------
Someone figured out my password. Now I have to rename my dog.

On Wed, 11 Sep 2013 12:50:04 -0400, "Jim Wilkins"
wrote:

"Ed Huntress" wrote in message
.. .
On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just
glued
to
the rear hatch. I'm thinking that if it was removed a gasket
could
be
installed, and hinges, gas springs, and a latch installed. So can
this
be done? Anyone here done this? I'm pretty sure that making the
hinge
assembly, latches, and handle won't present any real challenges.
After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a
silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly
stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

That was purely a description, not a prescription. If you find an
instance of a high-stress glue attachment its repair procedure and
materials should be helpful.

Glass is not among the materials I study much, but I suspect that,
in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.

--
Ed Huntress

If the glue ages and fails, like my professionally installed mirror, a
sharp maneuver could fling the hatch glass into another car's
windshield.

jsw

I know that rear view mirrors are glued on, as well as windshields and
rear windows. They use different glues. Rear view mirror glue is not
good at taking shocks, it's brittle. OTOH, regular windshield glue is
too soft. A rear window coming off could lead to a disaster so if I
attempt this I need to make sure that can't happen. Last night I
realized the only safe and practical way to make the window openable
is to mount it in a frame exactly the way it is mounted now and mount
the hinges and latch to the frame. I just laid a straight edge on the
window and it is curved in both X and Y. Making a frame to match this
compound curve would probably take me a long time. I should probably
give up on this idea unless I can get one of those pimp my ride type
shows to do it for me. Hmm.....
Eric

On Wed, 11 Sep 2013 00:39:54 -0400, Steve W. wrote:

wrote:

However if that vehicle is like many of the newer ones that glass is
probably a structural part of the hatch. You may need to add some extra
metal to the frame of the hatch to make up for the lack of the glass.

Chicken Little say "yup".

Do it if the trip is worth the time and possible new rear window.
Otherwise, find other ways to customize the car.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

On Wed, 11 Sep 2013 10:59:24 -0700, etpm wrote:

On Wed, 11 Sep 2013 12:50:04 -0400, "Jim Wilkins"
wrote:

"Ed Huntress" wrote in message
. ..
On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes in it won't work. I am pretty sure I have seen handles glued
to windows on cars but I'm not sure. The rear window is now just
glued to the rear hatch. I'm thinking that if it was removed a
gasket could be installed, and hinges, gas springs, and a latch
installed. So can this be done? Anyone here done this? I'm pretty
sure that making the hinge assembly, latches, and handle won't
present any real challenges. After all, I do have a complete mahine
shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

That was purely a description, not a prescription. If you find an
instance of a high-stress glue attachment its repair procedure and
materials should be helpful.

Glass is not among the materials I study much, but I suspect that, in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.

--
Ed Huntress

If the glue ages and fails, like my professionally installed mirror, a
sharp maneuver could fling the hatch glass into another car's
windshield.

jsw

I know that rear view mirrors are glued on, as well as windshields and
rear windows. They use different glues. Rear view mirror glue is not
good at taking shocks, it's brittle. OTOH, regular windshield glue is
too soft. A rear window coming off could lead to a disaster so if I
attempt this I need to make sure that can't happen. Last night I
realized the only safe and practical way to make the window openable is
to mount it in a frame exactly the way it is mounted now and mount the
hinges and latch to the frame. I just laid a straight edge on the window
and it is curved in both X and Y. Making a frame to match this compound
curve would probably take me a long time. I should probably give up on
this idea unless I can get one of those pimp my ride type shows to do it
for me. Hmm.....
Eric

I definitely think that if you want it to be safe you should arrange the
latches and hinges so that they'll hold the window in even if the glue
completely fails.

Perhaps have two straps running down from the hinges to the latches on
the outside of the window, with the window glued to those? Then the
worst that'll happen is that you unlatch the window, open it, and it
falls on your feet.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

On Wed, 11 Sep 2013 13:47:29 -0500, Tim Wescott
wrote:

On Wed, 11 Sep 2013 10:59:24 -0700, etpm wrote:

On Wed, 11 Sep 2013 12:50:04 -0400, "Jim Wilkins"
wrote:

"Ed Huntress" wrote in message
...
On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes in it won't work. I am pretty sure I have seen handles glued
to windows on cars but I'm not sure. The rear window is now just
glued to the rear hatch. I'm thinking that if it was removed a
gasket could be installed, and hinges, gas springs, and a latch
installed. So can this be done? Anyone here done this? I'm pretty
sure that making the hinge assembly, latches, and handle won't
present any real challenges. After all, I do have a complete mahine
shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

That was purely a description, not a prescription. If you find an
instance of a high-stress glue attachment its repair procedure and
materials should be helpful.

Glass is not among the materials I study much, but I suspect that, in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.

--
Ed Huntress

If the glue ages and fails, like my professionally installed mirror, a
sharp maneuver could fling the hatch glass into another car's
windshield.

jsw

I know that rear view mirrors are glued on, as well as windshields and
rear windows. They use different glues. Rear view mirror glue is not
good at taking shocks, it's brittle. OTOH, regular windshield glue is
too soft. A rear window coming off could lead to a disaster so if I
attempt this I need to make sure that can't happen. Last night I
realized the only safe and practical way to make the window openable is
to mount it in a frame exactly the way it is mounted now and mount the
hinges and latch to the frame. I just laid a straight edge on the window
and it is curved in both X and Y. Making a frame to match this compound
curve would probably take me a long time. I should probably give up on
this idea unless I can get one of those pimp my ride type shows to do it
for me. Hmm.....
Eric

I definitely think that if you want it to be safe you should arrange the
latches and hinges so that they'll hold the window in even if the glue
completely fails.

Perhaps have two straps running down from the hinges to the latches on
the outside of the window, with the window glued to those? Then the
worst that'll happen is that you unlatch the window, open it, and it
falls on your feet.

Aluminum channel, which you can bend by hand, has been used for
framing the tops of windshields on kit cars and some race cars for
decades.

--
Ed Huntress

wrote in message
...
I know that rear view mirrors are glued on, as well as windshields
and
rear windows. They use different glues. Rear view mirror glue is not
good at taking shocks, it's brittle. OTOH, regular windshield glue
is
too soft. A rear window coming off could lead to a disaster so if I
attempt this I need to make sure that can't happen. Last night I
realized the only safe and practical way to make the window openable
is to mount it in a frame exactly the way it is mounted now and
mount
the hinges and latch to the frame. I just laid a straight edge on
the
window and it is curved in both X and Y. Making a frame to match
this
compound curve would probably take me a long time. I should probably
give up on this idea unless I can get one of those pimp my ride type
shows to do it for me. Hmm.....
Eric

Perhaps you could find a rear hatch from a wreck that has at least the
glass area intact and see if you can reasonably fabricate a gasketed
frame to fit the opening. Then your car remains in service.

I suspect that if you taped a cardboard model of the glassless hatch
over the opening you might find access too limited. I found it
difficult to reach the front part of my 78 Accord hatchback's cargo
area without soiling my clothes with the dust or salt that quickly
accumulated on the back.
jsw

"Ed Huntress" wrote in message
...

Aluminum channel, which you can bend by hand, has been used for
framing the tops of windshields on kit cars and some race cars for
decades.

--
Ed Huntress

Maybe materials for making replacement RV windows would help?
http://www.easyrvwindows.com/rvwindows.html

jsw

On Wed, 11 Sep 2013 10:56:38 -0700, "Paul Hovnanian P.E."
wrote:

Ed Huntress wrote:

On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued
to
the rear hatch. I'm thinking that if it was removed a gasket could
be
installed, and hinges, gas springs, and a latch installed. So can
this
be done? Anyone here done this? I'm pretty sure that making the
hinge
assembly, latches, and handle won't present any real challenges.
After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

Glass is not among the materials I study much, but I suspect that, in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.


The glue may need to be somewhat flexible to allow different rates of
expansion between the glass and the frame. Or arrange the frame to be made
in parts than can slip or flex slightly as the glass expands/contracts.

If the rear window is already held in with glue, just use the same stuff.
They've already solved that problem.

The other alternative is to make a frame with a flange that will mate with a
standard windshield rubber gasket. The glass sits in one slot in the
gasket, the frame in another. Turning the gasket around (frame on the
outside, glass toward the inside) might allow the face of the rubber gasket
to act as a weather seal against the car body.
I keep thinking about this even though I'll probably not do it. My
thinking is that the frame should have a flange that protrudes into
the car interior about .5 inches. It should also have provisions for 8
clips, two per side, that trap the glass in case of glue failure. I
doubt that the glue would fail because I would be using the factory
glue. The flange is for stiffness and maybe for sealing. The way the
hatch is made provides for a standard type of seal that is already
being used in cars that have an openable rear window. I want the
opening window so that I can carry long items (over 8 feet long) and
so that I can have really good air flow on hot days. Of course the
real reason for this type of mod is to show off to all those young
whippersnappers out there who have one of these cars and the only
things custom are bolt on items. I have already figured out how to add
a cruise control that rotates with the steering wheel and the last of
the radio control parts just arrived Monday. I have bench tested the
wireless cruise control buttons and they work as planned.
Eric

wrote in message
...
... I want the
opening window so that I can carry long items (over 8 feet long) and
so that I can have really good air flow on hot days.

I used to carry 12' lumber for theatre sets in a Civic hatchback. I
had to have all the front windows open and the fan on high to keep the
exhaust that the open hatch sucked in bearable. The car I have now
holds 10' pipe with the hatch closed, but for 12' and sheet material
the better mod is a roof rack and tiedowns under the bumper corners. I
bought the factory rack that screws to studs hidden in the roof
reinforcing channels. For imports with tiedown eyes a stainless screw
link in each is enough to protect the cargo rope from cutting.
http://www.rockclimbing.com/images/g...10030888_3.jpg

Of course the
real reason for this type of mod is to show off to all those young
whippersnappers out there who have one of these cars and the only
things custom are bolt on items. I have already figured out how to
add
a cruise control that rotates with the steering wheel and the last
of
the radio control parts just arrived Monday. I have bench tested the
wireless cruise control buttons and they work as planned.
Eric

I reupholstered a Beetle once but the only people who were impressed
wanted me to do their cars, for cheap.

jsw

On Wed, 11 Sep 2013 10:56:38 -0700, "Paul Hovnanian P.E."
wrote:

Ed Huntress wrote:

On Wed, 11 Sep 2013 08:17:46 -0400, "Jim Wilkins"
wrote:

"Artemus" wrote in message
...

wrote in message
...
So I have this wild idea to make the rear window on my Scion xB
openable. It is of course made from tempered glass and so making
holes
in it won't work. I am pretty sure I have seen handles glued to
windows on cars but I'm not sure. The rear window is now just glued
to
the rear hatch. I'm thinking that if it was removed a gasket could
be
installed, and hinges, gas springs, and a latch installed. So can
this
be done? Anyone here done this? I'm pretty sure that making the
hinge
assembly, latches, and handle won't present any real challenges.
After
all, I do have a complete mahine shop and I am a machinist.
Eric

Think about the other end. Windshields are glued in with a silicone
adhesive and the rear view mirrors are glued to the glass too.
Art

The latch, wiper, struts, brake light and hinges on my Honda's glass
upper hatch are attached with thru-hole fittings. The heater grid
contacts are bonded to the glass.

Art's point, though, is that "tempered" glass is very highly stressed.
The surfaces are in compression and the core is in tension. If you
drill it, or even scratch it deeply, it *may* propagate a crack
through the glass and shatter it into chunks (not sharp shards).

Glass is not among the materials I study much, but I suspect that, in
production, they either do their drilling while the glass is in the
annealed state, or they have a way of locally annealing it after
tempering.

As for gluing to it, there has been good advice in this thread. You
can get a very strong bond with the right materials and technique.


The glue may need to be somewhat flexible to allow different rates of
expansion between the glass and the frame. Or arrange the frame to be made
in parts than can slip or flex slightly as the glass expands/contracts.

If the rear window is already held in with glue, just use the same stuff.
They've already solved that problem.

The other alternative is to make a frame with a flange that will mate with a
standard windshield rubber gasket. The glass sits in one slot in the
gasket, the frame in another. Turning the gasket around (frame on the
outside, glass toward the inside) might allow the face of the rubber gasket
to act as a weather seal against the car body.

I'm kinda surprised that no PEs have suggested that the existing glass
window wasn't designed to be handled in the manner Eric is suggesting.
That's some major torque in what? A 2sq/in area on each side.

--
[Television is] the triumph of machine over people.
-- Fred Allen

On Wed, 11 Sep 2013 15:37:43 -0400
"Jim Wilkins" wrote:

wrote in message
.. .
... I want the
opening window so that I can carry long items (over 8 feet long) and
so that I can have really good air flow on hot days.

I used to carry 12' lumber for theatre sets in a Civic hatchback. I
had to have all the front windows open and the fan on high to keep the
exhaust that the open hatch sucked in bearable. The car I have now
holds 10' pipe with the hatch closed, but for 12' and sheet material
the better mod is a roof rack and tiedowns under the bumper corners. I
bought the factory rack that screws to studs hidden in the roof
reinforcing channels. For imports with tiedown eyes a stainless screw
link in each is enough to protect the cargo rope from cutting.
http://www.rockclimbing.com/images/g...10030888_3.jpg
snip

I never got around to it but thought about bolting/welding two Reese
style hitch receivers sideways. One on the right side of the front
bumper and the other on the back bumper. Then I was going to make
two special slide-ins for them that could cradle long stuff. This way
the stuff would ride relatively low and you could use the full length
of your vehicle to keep it from sticking out front and rear. Just pop
the pins, slide the cradles out and store them when not needed.

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

"Larry Jaques" wrote in message
...

I'm kinda surprised that no PEs have suggested that the existing
glass
window wasn't designed to be handled in the manner Eric is
suggesting.
That's some major torque in what? A 2sq/in area on each side.


Ungluing the window should reduce the load on the glass unless its
latch is too constraining. My hatch is all glass below the hinge bar.
The latch is a hook through a squared loop, like a car door, that
allows some sideways motion. Unlike a door there are no locating
wedges to control side play. However the lower door which supports the
spare wheel has a large metal "wedge striker" restraining it on the
latch side.

You bought the HF solar panel kit, right? One of the Schottkys that
blocks reverse leakage out to the panels failed short on mine. I
replaced both with one 10A 50V Schottky diode. A temporary silicon
diode's higher voltage drop cost about 0.1A at 2A.

http://www.amazon.com/dp/B0056RHMCG/..._26725410_item
I needed several Si diode replacements elsewhere, and shipping from
other 'cheaper' sources brought them to about the same total. Their
reverse leakage jumps above ~100uA at 48-50V as though they were
rejects from an automatic tester. It's respectably low up to 30V.
Above 4A forward current they heat up, as shown by a dropping VF.
Below it VF holds steady.

jsw

On Thu, 12 Sep 2013 11:15:21 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .

I'm kinda surprised that no PEs have suggested that the existing
glass
window wasn't designed to be handled in the manner Eric is
suggesting.
That's some major torque in what? A 2sq/in area on each side.


Ungluing the window should reduce the load on the glass unless its
latch is too constraining. My hatch is all glass below the hinge bar.
The latch is a hook through a squared loop, like a car door, that
allows some sideways motion. Unlike a door there are no locating
wedges to control side play. However the lower door which supports the
spare wheel has a large metal "wedge striker" restraining it on the
latch side.

I thought he was removing the glass from the frame to hinge it
directly. That seems like a whole lot more stress to me.


You bought the HF solar panel kit, right? One of the Schottkys that
blocks reverse leakage out to the panels failed short on mine. I
replaced both with one 10A 50V Schottky diode. A temporary silicon
diode's higher voltage drop cost about 0.1A at 2A.

Yeah. A tenth amp drop beats zero output, huh?



http://www.amazon.com/dp/B0056RHMCG/..._26725410_item
I needed several Si diode replacements elsewhere, and shipping from
other 'cheaper' sources brought them to about the same total. Their
reverse leakage jumps above ~100uA at 48-50V as though they were
rejects from an automatic tester. It's respectably low up to 30V.
Above 4A forward current they heat up, as shown by a dropping VF.
Below it VF holds steady.

What's your max wattage now from a set of HF panels? I haven't yet
hooked up my emergency lights to the panels. This is my busiest time
for work, so I got as far as cutting conduit and routing the cables
through the wall into my office (central location for the controller),
but I'll wait until a cool morning comes along to climb up in to the
attic to run the wiring. It has been 100F here lately. It's supposed
to rain next week, so that might give me the time and conditions I
need to finish the installation.

These little $3 9W cool white LEDs work well in these $2.99 globe
fixtures. The globe disperses the spot into a floodlike output.
Oh, the 9W LEDs consume 7W, so they're running underpowered and should
have a really nice lifetime. http://tinyurl.com/lnszqr9 $6 cheaper
now. http://tinyurl.com/lokpctl $2.95 ea + $2.99 per shipment s/h.
I can read under one of them, mounted directly overhead on the
ceiling. In open fixtures, they'd be good spots.

--
[Television is] the triumph of machine over people.
-- Fred Allen

"Larry Jaques" wrote in message
...
On Thu, 12 Sep 2013 11:15:21 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
. ..

You bought the HF solar panel kit, right? One of the Schottkys that
blocks reverse leakage out to the panels failed short on mine. I
replaced both with one 10A 50V Schottky diode. A temporary silicon
diode's higher voltage drop cost about 0.1A at 2A.

Yeah. A tenth amp drop beats zero output, huh?

Here's a link to a schematic which nearly matches the charger in my
two-year-old aluminum-framed panel kit:
http://solarpanelkitatharborfreight....eight-charge-1
The Schottkys are D1 and D2, in series between the panel and battery
on the positive side. When one failed short the charger kept working
normally. Q6 connects the negative side.

I use a separate double-pole toggle switch to isolate the battery from
the charger when it's not in use, since I don't leave Harbor Freight
electronics powered up when unattended*, so I hadn't noticed if the
panels discharge the battery at night. I found the problem during
inspection of the wiring.

F1 and F2 are swapped on the schematic vs the circuit board. The UF400
current limiter is F1, the 4A ATC fuse on the back panel is F2. The
output jacks show PCB pin numbers but not the connectors or silkscreen
labels. Mine turns off at 14.4V, back on at 13.1V to restrict battery
overcharge and water loss.

I wired a separate lighter outlet to the battery terminals because the
front panel one won't supply the full bootup current to a laptop
auto-air power adapter. I saw the voltage drop rather than the fuse
blow so perhaps Q6 hit its limit.


What's your max wattage now from a set of HF panels?


The nominal output is 0.86A at 17.5V, or 15W per panel. The current
isn't much higher into a 12V battery which means the power you
actually get is lower. The kit can just about keep up with my laptop's
20W-35W demand.

When they were new I think I saw as much as 0.9A per panel, but after
two years I rarely see much over 0.7A, 2.1A total, on the analog
(unpowered) ammeter I added before the controller input, the safer
side. A meter on the battery side needs to tolerate more current in
either direction. http://www.futurlec.com/Panel_Meters.shtml
Amazon delivers them faster.
http://www.amazon.com/Amico-Class-An...analog+ammeter
They are NOT precision instruments, but are good enough to detect
problems and cheap enough to leave outdoors.

*Testing a cigarette-lighter DC-to-AC inverter of Chinese origin
showed it would happily drain the battery down to 7V though it claimed
to have a low battery shutoff.

jsw

On Fri, 13 Sep 2013 10:01:37 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Thu, 12 Sep 2013 11:15:21 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
...

You bought the HF solar panel kit, right? One of the Schottkys that
blocks reverse leakage out to the panels failed short on mine. I
replaced both with one 10A 50V Schottky diode. A temporary silicon
diode's higher voltage drop cost about 0.1A at 2A.

Yeah. A tenth amp drop beats zero output, huh?

Here's a link to a schematic which nearly matches the charger in my
two-year-old aluminum-framed panel kit:
http://solarpanelkitatharborfreight....eight-charge-1

I think you posted that a few months ago, but I grabbed it again, JIC.
Danke.


The Schottkys are D1 and D2, in series between the panel and battery
on the positive side. When one failed short the charger kept working
normally. Q6 connects the negative side.

Why the 2nd diode on a DC-only circuit? Reverse polarity protection?


I use a separate double-pole toggle switch to isolate the battery from
the charger when it's not in use, since I don't leave Harbor Freight
electronics powered up when unattended*, so I hadn't noticed if the
panels discharge the battery at night. I found the problem during
inspection of the wiring.

I have some extra switches and may do that same thing shortly.

The rain has been called off, so I'll be working most days, including
tomorrow. When I do get a day off, it has to be a real down day for
my body to come back and be able to handle the next week's work. It's
hell getting old.


F1 and F2 are swapped on the schematic vs the circuit board. The UF400
current limiter is F1, the 4A ATC fuse on the back panel is F2. The
output jacks show PCB pin numbers but not the connectors or silkscreen
labels. Mine turns off at 14.4V, back on at 13.1V to restrict battery
overcharge and water loss.

Bueno. Regulation is a very good thing for LA batts.


I wired a separate lighter outlet to the battery terminals because the
front panel one won't supply the full bootup current to a laptop
auto-air power adapter. I saw the voltage drop rather than the fuse
blow so perhaps Q6 hit its limit.

I know one lighter socket is limited but I thought the other was full
current. (I blew the fuse trying out my 12v car heater but it worked
fine in the other socket.



What's your max wattage now from a set of HF panels?


The nominal output is 0.86A at 17.5V, or 15W per panel. The current
isn't much higher into a 12V battery which means the power you
actually get is lower. The kit can just about keep up with my laptop's
20W-35W demand.

Reminder to self: check -my- laptop's current draw.


When they were new I think I saw as much as 0.9A per panel, but after
two years I rarely see much over 0.7A, 2.1A total, on the analog
(unpowered) ammeter I added before the controller input, the safer
side. A meter on the battery side needs to tolerate more current in
either direction. http://www.futurlec.com/Panel_Meters.shtml
Amazon delivers them faster.
http://www.amazon.com/Amico-Class-An...analog+ammeter
They are NOT precision instruments, but are good enough to detect
problems and cheap enough to leave outdoors.

I went the Amazon route. It's in the queue, too. I was going to wire
it up at the controller, inside. Are you using it at the battery to
check charging rates per panel? Maybe I'll rethink this.



*Testing a cigarette-lighter DC-to-AC inverter of Chinese origin
showed it would happily drain the battery down to 7V though it claimed
to have a low battery shutoff.

Oops. g I'll have to check my finest HF product for that, too.

--
[Television is] the triumph of machine over people.
-- Fred Allen

"Larry Jaques" wrote in message
...
On Fri, 13 Sep 2013 10:01:37 -0400, "Jim Wilkins"
wrote:

The Schottkys are D1 and D2, in series between the panel and battery
on the positive side. When one failed short the charger kept working
normally. Q6 connects the negative side.

Why the 2nd diode on a DC-only circuit? Reverse polarity
protection?

Likely inadeqate current rating. They are 3A diodes in a 4A circuit.
The problem is that if one heats up its forward voltage will drop and
it will hog all the current, assuming they were initially matched and
shared evenly (Ha!). I may have caused that by adding two more solar
panels which pushed the current over 3A.
http://en.wikipedia.org/wiki/Thermal_runaway
"Typically, one device may have a slightly lower resistance, and thus
draws more current, heating it more than its sibling devices, causing
its resistance to drop further. The electrical load ends up funneling
into a single device, which then rapidly fails."

The replacement 10A diode is larger and doesn't fit under the heatsink
clamp. I hung it off the side of the board.

When I do get a day off, it has to be a real down day for
my body to come back and be able to handle the next week's work.
It's
hell getting old.

Monday I cleared some brush as volunteer work, then spent the week
nearly immobile while my knee healed. I need the exercise but not the
injuries, so I put in for the less physically demanding building
maintenance committee. I'm a much better carpenter, electrician and
plumber than landscaper anyway.

The kit can just about keep up with my laptop's
20W-35W demand.

Reminder to self: check -my- laptop's current draw.
...
I went the Amazon route. It's in the queue, too. I was going to
wire
it up at the controller, inside. Are you using it at the battery to
check charging rates per panel? Maybe I'll rethink this.

The analog meter is wired with 2-pin trailer connectors like the newer
plastic-framed panels use
http://www.newegg.com/Product/Produc...9SIA1SR0H18836
so I can insert it into the circuit indoors before the controller to
show that everything is still working, or out at the panels to aim
them for maximum output. I use a digital multimeter to check
individual panel output with much better accuracy.

*Testing a cigarette-lighter DC-to-AC inverter of Chinese origin
showed it would happily drain the battery down to 7V though it
claimed
to have a low battery shutoff.

Oops. g I'll have to check my finest HF product for that, too.

That inverter came from a second-hand computer store, marked down, in
an unlabelled bag. It tested OK except for the failed low-voltage
limit and should be fine in the car where the ignition switch controls
the lighter outlets. The HF inverters I have do shut off when the
battery drops to around 10V. Thus they make good battery discharge
test loads with a lamp or crock pot (safer) plugged in.

If you don't have a data acquisition system, this free program can
record the discharge of a laptop battery, and capture the time when an
inverter or UPS powering the laptop shuts off and it switches to
internal battery power.
http://www.hwinfo.com/download.php
The program's continual file writes keep the hard drive active, more
or less as you would if using the laptop on battery.

I tested the inverter's low voltage behavior with a 30V 5A lab supply
like this, bought locally:
http://smart-prototyping.com/index.p...product_id=177
Lab power supplies with adjustable current limits are great for
measuring component parameters IF you know what you are doing and are
careful. They are good fire-starters if you don't.
http://electrojumble.org/reforming.htm

That one makes me nervous with loud relay clunks from inside as I turn
up the voltage. I don't know if the output can briefly spike. It may
have a capacitor downstream of the current regulator because I've seen
readings start high and then settle to the regulated limit, and the
current readout isn't completely stable at high current and low
voltage such as measuring the forward drop of the Schottkys. Otherwise
it's been a good lab supply and universal battery charger / salvager
for the price.
http://batteryuniversity.com/learn/a...alizing_charge

I use my homebrew Variac power supply (0-40V, 20A) to check
flea-market laptop 12VDC laptop power adapters since they can draw
more than 5A, as can 100W cigarette-lighter inverters. A laptop's
current demand is beyond user control so I made a custom input jack
from brass tubing to connect the adapter to big Franken-rheostat
loads:
http://www.alliedelec.com/images/pro...l/70022534.jpg

In practice these Dells take 2A to 2.5A at 12V but once a D630 that
was recharging a low battery decided to pull all it could until the
adapter got very hot.
jsw

On Sat, 14 Sep 2013 11:53:48 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Fri, 13 Sep 2013 10:01:37 -0400, "Jim Wilkins"
wrote:

The Schottkys are D1 and D2, in series between the panel and battery
on the positive side. When one failed short the charger kept working
normally. Q6 connects the negative side.

Why the 2nd diode on a DC-only circuit? Reverse polarity
protection?

Likely inadeqate current rating. They are 3A diodes in a 4A circuit.
The problem is that if one heats up its forward voltage will drop and
it will hog all the current, assuming they were initially matched and
shared evenly (Ha!). I may have caused that by adding two more solar
panels which pushed the current over 3A.

If they're in series, Jim, they both pass the same current. The
current "hogging" you describe can occur in parallel circuits.

And if they're in series, they each carry the *full* current. They
divide the voltage.

--
Ed Huntress


http://en.wikipedia.org/wiki/Thermal_runaway
"Typically, one device may have a slightly lower resistance, and thus
draws more current, heating it more than its sibling devices, causing
its resistance to drop further. The electrical load ends up funneling
into a single device, which then rapidly fails."

The replacement 10A diode is larger and doesn't fit under the heatsink
clamp. I hung it off the side of the board.

When I do get a day off, it has to be a real down day for
my body to come back and be able to handle the next week's work.
It's
hell getting old.

Monday I cleared some brush as volunteer work, then spent the week
nearly immobile while my knee healed. I need the exercise but not the
injuries, so I put in for the less physically demanding building
maintenance committee. I'm a much better carpenter, electrician and
plumber than landscaper anyway.

The kit can just about keep up with my laptop's
20W-35W demand.

Reminder to self: check -my- laptop's current draw.
...
I went the Amazon route. It's in the queue, too. I was going to
wire
it up at the controller, inside. Are you using it at the battery to
check charging rates per panel? Maybe I'll rethink this.

The analog meter is wired with 2-pin trailer connectors like the newer
plastic-framed panels use
http://www.newegg.com/Product/Produc...9SIA1SR0H18836
so I can insert it into the circuit indoors before the controller to
show that everything is still working, or out at the panels to aim
them for maximum output. I use a digital multimeter to check
individual panel output with much better accuracy.

*Testing a cigarette-lighter DC-to-AC inverter of Chinese origin
showed it would happily drain the battery down to 7V though it
claimed
to have a low battery shutoff.

Oops. g I'll have to check my finest HF product for that, too.

That inverter came from a second-hand computer store, marked down, in
an unlabelled bag. It tested OK except for the failed low-voltage
limit and should be fine in the car where the ignition switch controls
the lighter outlets. The HF inverters I have do shut off when the
battery drops to around 10V. Thus they make good battery discharge
test loads with a lamp or crock pot (safer) plugged in.

If you don't have a data acquisition system, this free program can
record the discharge of a laptop battery, and capture the time when an
inverter or UPS powering the laptop shuts off and it switches to
internal battery power.
http://www.hwinfo.com/download.php
The program's continual file writes keep the hard drive active, more
or less as you would if using the laptop on battery.

I tested the inverter's low voltage behavior with a 30V 5A lab supply
like this, bought locally:
http://smart-prototyping.com/index.p...product_id=177
Lab power supplies with adjustable current limits are great for
measuring component parameters IF you know what you are doing and are
careful. They are good fire-starters if you don't.
http://electrojumble.org/reforming.htm

That one makes me nervous with loud relay clunks from inside as I turn
up the voltage. I don't know if the output can briefly spike. It may
have a capacitor downstream of the current regulator because I've seen
readings start high and then settle to the regulated limit, and the
current readout isn't completely stable at high current and low
voltage such as measuring the forward drop of the Schottkys. Otherwise
it's been a good lab supply and universal battery charger / salvager
for the price.
http://batteryuniversity.com/learn/a...alizing_charge

I use my homebrew Variac power supply (0-40V, 20A) to check
flea-market laptop 12VDC laptop power adapters since they can draw
more than 5A, as can 100W cigarette-lighter inverters. A laptop's
current demand is beyond user control so I made a custom input jack
from brass tubing to connect the adapter to big Franken-rheostat
loads:
http://www.alliedelec.com/images/pro...l/70022534.jpg

In practice these Dells take 2A to 2.5A at 12V but once a D630 that
was recharging a low battery decided to pull all it could until the
adapter got very hot.
jsw

"Ed Huntress" wrote in message
news
On Sat, 14 Sep 2013 11:53:48 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
. ..
On Fri, 13 Sep 2013 10:01:37 -0400, "Jim Wilkins"
wrote:

The Schottkys are D1 and D2, in series between the panel and
battery
on the positive side. When one failed short the charger kept
working
normally. Q6 connects the negative side.

Why the 2nd diode on a DC-only circuit? Reverse polarity
protection?

Likely inadeqate current rating. They are 3A diodes in a 4A circuit.
The problem is that if one heats up its forward voltage will drop
and
it will hog all the current, assuming they were initially matched
and
shared evenly (Ha!). I may have caused that by adding two more solar
panels which pushed the current over 3A.

If they're in series, Jim, they both pass the same current. The
current "hogging" you describe can occur in parallel circuits.

And if they're in series, they each carry the *full* current. They
divide the voltage.

--
Ed Huntress

You didn't look at the schematic I referenced, did you? The two diodes
are in parallel with each other and hopefully share current. The PAIR
is in series between the panel and the battery, so when one shorted
the charger continued to work.
jsw

On Sat, 14 Sep 2013 13:46:14 -0400, "Jim Wilkins"
wrote:

"Ed Huntress" wrote in message
news
On Sat, 14 Sep 2013 11:53:48 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
...
On Fri, 13 Sep 2013 10:01:37 -0400, "Jim Wilkins"
wrote:

The Schottkys are D1 and D2, in series between the panel and
battery
on the positive side. When one failed short the charger kept
working
normally. Q6 connects the negative side.

Why the 2nd diode on a DC-only circuit? Reverse polarity
protection?

Likely inadeqate current rating. They are 3A diodes in a 4A circuit.
The problem is that if one heats up its forward voltage will drop
and
it will hog all the current, assuming they were initially matched
and
shared evenly (Ha!). I may have caused that by adding two more solar
panels which pushed the current over 3A.

If they're in series, Jim, they both pass the same current. The
current "hogging" you describe can occur in parallel circuits.

And if they're in series, they each carry the *full* current. They
divide the voltage.

--
Ed Huntress

You didn't look at the schematic I referenced, did you?

Nope, I was going from what I could make out from your words.

I realize you know electronics, but it looked like you mispoke, from
the way your description read.

The two diodes
are in parallel with each other and hopefully share current. The PAIR
is in series between the panel and the battery, so when one shorted
the charger continued to work.
jsw

Yeah, I see it.

--
Ed Huntress

"Ed Huntress" wrote in message
...
On Sat, 14 Sep 2013 13:46:14 -0400, "Jim Wilkins"
wrote:


You didn't look at the schematic I referenced, did you?

Nope, I was going from what I could make out from your words.

I realize you know electronics, but it looked like you mispoke, from
the way your description read.


That's why I practice on an audience that doesn't sign my paycheck.
jsw

On Sat, 14 Sep 2013 11:53:48 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Fri, 13 Sep 2013 10:01:37 -0400, "Jim Wilkins"
wrote:

The Schottkys are D1 and D2, in series between the panel and battery
on the positive side. When one failed short the charger kept working
normally. Q6 connects the negative side.

Why the 2nd diode on a DC-only circuit? Reverse polarity
protection?

Likely inadeqate current rating. They are 3A diodes in a 4A circuit.
The problem is that if one heats up its forward voltage will drop and
it will hog all the current, assuming they were initially matched and
shared evenly (Ha!). I may have caused that by adding two more solar
panels which pushed the current over 3A.
http://en.wikipedia.org/wiki/Thermal_runaway
"Typically, one device may have a slightly lower resistance, and thus
draws more current, heating it more than its sibling devices, causing
its resistance to drop further. The electrical load ends up funneling
into a single device, which then rapidly fails."

The replacement 10A diode is larger and doesn't fit under the heatsink
clamp. I hung it off the side of the board.

....which resulted in better cooling. Win/win, wot?


When I do get a day off, it has to be a real down day for
my body to come back and be able to handle the next week's work.
It's
hell getting old.

Monday I cleared some brush as volunteer work, then spent the week
nearly immobile while my knee healed. I need the exercise but not the
injuries, so I put in for the less physically demanding building
maintenance committee. I'm a much better carpenter, electrician and
plumber than landscaper anyway.

I rested on my knees while masking the foundation a couple times
yesterday and my knees are telling me today that I should -never- do
that without padding. Yeah, we can all do without injuries. I added a
few cutouts of 1/4" foam to my HF knee pads and they're much more
comfy now. Wish I'd worn 'em.


The kit can just about keep up with my laptop's
20W-35W demand.

Reminder to self: check -my- laptop's current draw.
...
I went the Amazon route. It's in the queue, too. I was going to
wire
it up at the controller, inside. Are you using it at the battery to
check charging rates per panel? Maybe I'll rethink this.

The analog meter is wired with 2-pin trailer connectors like the newer
plastic-framed panels use
http://www.newegg.com/Product/Produc...9SIA1SR0H18836
so I can insert it into the circuit indoors before the controller to
show that everything is still working, or out at the panels to aim

Nice!


them for maximum output. I use a digital multimeter to check
individual panel output with much better accuracy.

Yeah, that's for sure.


*Testing a cigarette-lighter DC-to-AC inverter of Chinese origin
showed it would happily drain the battery down to 7V though it
claimed
to have a low battery shutoff.

Oops. g I'll have to check my finest HF product for that, too.

That inverter came from a second-hand computer store, marked down, in
an unlabelled bag. It tested OK except for the failed low-voltage
limit and should be fine in the car where the ignition switch controls
the lighter outlets. The HF inverters I have do shut off when the
battery drops to around 10V. Thus they make good battery discharge
test loads with a lamp or crock pot (safer) plugged in.

If you don't have a data acquisition system, this free program can
record the discharge of a laptop battery, and capture the time when an
inverter or UPS powering the laptop shuts off and it switches to
internal battery power.
http://www.hwinfo.com/download.php
The program's continual file writes keep the hard drive active, more
or less as you would if using the laptop on battery.

Tanks.


I tested the inverter's low voltage behavior with a 30V 5A lab supply
like this, bought locally:
http://smart-prototyping.com/index.p...product_id=177

Sweet! I've never seemed to have a regular need for a variable supply
so I've never bought one. I usually rely on wall warts.


Lab power supplies with adjustable current limits are great for
measuring component parameters IF you know what you are doing and are
careful. They are good fire-starters if you don't.
http://electrojumble.org/reforming.htm

Interesting.


That one makes me nervous with loud relay clunks from inside as I turn
up the voltage. I don't know if the output can briefly spike. It may
have a capacitor downstream of the current regulator because I've seen
readings start high and then settle to the regulated limit, and the

Both my Makita and Ryobi battery chargers have massive caps (or
inductive loads) in them and they cause visible/audible sparks when
they're plugged in each time. That just bothers the crap out of me.


current readout isn't completely stable at high current and low
voltage such as measuring the forward drop of the Schottkys. Otherwise
it's been a good lab supply and universal battery charger / salvager
for the price.
http://batteryuniversity.com/learn/a...alizing_charge

That's something for me to think about for the future.


I use my homebrew Variac power supply (0-40V, 20A) to check
flea-market laptop 12VDC laptop power adapters since they can draw
more than 5A, as can 100W cigarette-lighter inverters. A laptop's
current demand is beyond user control so I made a custom input jack
from brass tubing to connect the adapter to big Franken-rheostat
loads:
http://www.alliedelec.com/images/pro...l/70022534.jpg

Big honker, ain't it?


In practice these Dells take 2A to 2.5A at 12V but once a D630 that
was recharging a low battery decided to pull all it could until the
adapter got very hot.

That's never any fun. (sniff,sniff...What's BURNING?)

--
Try not to become a man of success but
rather try to become a man of value.
--Albert Einstein

"Larry Jaques" wrote in message
...
On Sat, 14 Sep 2013 11:53:48 -0400, "Jim Wilkins"
wrote:

The replacement 10A diode is larger and doesn't fit under the
heatsink
clamp. I hung it off the side of the board.

...which resulted in better cooling. Win/win, wot?

I hope so. The physically larger 10A diode seemed OK at the panels'
max current. I raised the current until the diode got hot enough that
the forward drop crept downward.

I tested the inverter's low voltage behavior with a 30V 5A lab
supply
like this, bought locally:
http://smart-prototyping.com/index.p...product_id=177

Sweet! I've never seemed to have a regular need for a variable
supply
so I've never bought one. I usually rely on wall warts.

Mine have paid for themselves by revivifying dead power tool
batteries.
http://www.instructables.com/id/Brin...-Back-To-Life/
It's like voodoo, you have to know the ritual and make a sacrifice,
and you get at best a short-lived zombie rather than a healthy
subject. The safest way is to make a condemned prisoner do it while
you watch through binoculars. The usual procedure is to assign your
obedient lab tech Jim to do it while you take a long lunch.

When I was learning the intricacies of op-amp measurement circuits OJT
I realized that voltage can just sit there but current HAS to be
accounted for, and began thinking in terms of it, and how to control
and measure it. External meters don't work as well as a power supply
that shows current directly without a voltage drop across the meter
and jumper wires to consider. The big advantage of a lab supply is its
adjustable current limit which protects the load, and sometimes the
user.

These are fantastic if someone else pays for them:
http://www.home.agilent.com/en/pc-85...?&cc=US&lc=eng

and this has the capability of the 4-quadrant V-I supply that is the
heart of an automated analog semiconductor tester:
http://www.keithley.com/products/dca...rpose/?mn=2400
http://en.wikipedia.org/wiki/Automatic_test_equipment

4-quadrant means it can source or sink current in any combination of +
or -, like big op amps. Regulated power supplies may not take well to
a higher external voltage source forcing current back in, like if the
line power fails while charging a battery. I needed the extra
Schottkys to replace Si diodes that I attached to alligator clips and
connect in series with batteries I'm charging.

Cheap import lab supplies are good enough for my home experimenting,
such as measuring the resistance of a motor or antenna by forcing 1
Amp through it and reading milliOhms as milliVolts. Even a $4 HF DVM
will resolve tenths of a milliOhm that way. The power supply's output
voltage can be turned down very low so an open shouldn't damage the
circuit being checked, for example the wiring harness of an old
vehicle.

I use my homebrew Variac power supply (0-40V, 20A)
Big honker, ain't it?

It won't do both at once. I was looking for parts at a flea market to
complete a less ambitious one when I found the salvaged front panel,
with a 10A Variac and 40V and 20A meters, so I used the other
components I had already collected to resurrect it. It's not regulated
(yet) but good enough to quickly charge a dead battery or bench-test
heater and wiper motors that need more than the 5A limit of my lab
supplies. I don't like to connect sickly, sluggish DC motors directly
to a battery. It's safer to turn up the voltage on them slowly while
watching the current.

I've measured the DC current or AC power most of my antique
electronics consume and written it on them for when they need work
later. Yesterday I extended the wiring to my 1950's TV antenna rotator
and then watched the power the controller drew when turned back on to
confirm I hadn't miswired it. Now I can unplug it where it comes into
the basement instead of going out in the rain when lightning is
predicted.
jsw

On Sun, 15 Sep 2013 10:12:52 -0400, "Jim Wilkins"
wrote:

"Larry Jaques" wrote in message
.. .
On Sat, 14 Sep 2013 11:53:48 -0400, "Jim Wilkins"
wrote:

The replacement 10A diode is larger and doesn't fit under the
heatsink
clamp. I hung it off the side of the board.

...which resulted in better cooling. Win/win, wot?

I hope so. The physically larger 10A diode seemed OK at the panels'
max current. I raised the current until the diode got hot enough that
the forward drop crept downward.

I tested the inverter's low voltage behavior with a 30V 5A lab
supply
like this, bought locally:
http://smart-prototyping.com/index.p...product_id=177

Sweet! I've never seemed to have a regular need for a variable
supply
so I've never bought one. I usually rely on wall warts.

Mine have paid for themselves by revivifying dead power tool
batteries.
http://www.instructables.com/id/Brin...-Back-To-Life/
It's like voodoo, you have to know the ritual and make a sacrifice,
and you get at best a short-lived zombie rather than a healthy
subject. The safest way is to make a condemned prisoner do it while
you watch through binoculars. The usual procedure is to assign your
obedient lab tech Jim to do it while you take a long lunch.

Grok that. g


When I was learning the intricacies of op-amp measurement circuits OJT
I realized that voltage can just sit there but current HAS to be
accounted for, and began thinking in terms of it, and how to control
and measure it. External meters don't work as well as a power supply
that shows current directly without a voltage drop across the meter
and jumper wires to consider. The big advantage of a lab supply is its
adjustable current limit which protects the load, and sometimes the
user.

Yeah, current limiting seems like the way to go for safety. I don't
recall seeing that feature on any of the old supplies I ever worked
with, but it's been awhile. I could have forgotten.


These are fantastic if someone else pays for them:
http://www.home.agilent.com/en/pc-85...?&cc=US&lc=eng

A couple o' multis, please!


and this has the capability of the 4-quadrant V-I supply that is the
heart of an automated analog semiconductor tester:
http://www.keithley.com/products/dca...rpose/?mn=2400
http://en.wikipedia.org/wiki/Automatic_test_equipment

Nice.


4-quadrant means it can source or sink current in any combination of +
or -, like big op amps. Regulated power supplies may not take well to
a higher external voltage source forcing current back in, like if the
line power fails while charging a battery. I needed the extra
Schottkys to replace Si diodes that I attached to alligator clips and
connect in series with batteries I'm charging.

I found a pack of 10 on eBay for $7.78, delivered. You made a good
point of the most common failure point for the controllers. I guess I
could wire the inverter (+ soldering iron) directly to the battery to
work on the controller during an outage.


Cheap import lab supplies are good enough for my home experimenting,
such as measuring the resistance of a motor or antenna by forcing 1
Amp through it and reading milliOhms as milliVolts. Even a $4 HF DVM
will resolve tenths of a milliOhm that way. The power supply's output
voltage can be turned down very low so an open shouldn't damage the
circuit being checked, for example the wiring harness of an old
vehicle.

Huh? How can an open harm a circuit? (Other than arcing, and its
resultant damage and chaos?)


I used 9v batteries to check for opens and shorts in wiring harnesses
when I wrenched for the body shop. Lots of fenders were driven into
the looms when the bodies crumpled. I repaired and retaped (miles)
many a harness, since it was usually cheaper to repair than it would
be to replace it. In most instances, it was only one or two wires
which were damaged (usually severed.)



I use my homebrew Variac power supply (0-40V, 20A)
Big honker, ain't it?

It won't do both at once. I was looking for parts at a flea market to
complete a less ambitious one when I found the salvaged front panel,
with a 10A Variac and 40V and 20A meters, so I used the other
components I had already collected to resurrect it. It's not regulated
(yet) but good enough to quickly charge a dead battery or bench-test
heater and wiper motors that need more than the 5A limit of my lab
supplies. I don't like to connect sickly, sluggish DC motors directly
to a battery. It's safer to turn up the voltage on them slowly while
watching the current.

Aw, ya wuss!


I've measured the DC current or AC power most of my antique
electronics consume and written it on them for when they need work
later. Yesterday I extended the wiring to my 1950's TV antenna rotator
and then watched the power the controller drew when turned back on to
confirm I hadn't miswired it. Now I can unplug it where it comes into
the basement instead of going out in the rain when lightning is
predicted.

You live in that kind of area, eh?

--
Try not to become a man of success but
rather try to become a man of value.
--Albert Einstein

On 2013-09-15, Larry Jaques wrote:
On Sun, 15 Sep 2013 10:12:52 -0400, "Jim Wilkins"
wrote:

[ ... ]

When I was learning the intricacies of op-amp measurement circuits OJT
I realized that voltage can just sit there but current HAS to be
accounted for, and began thinking in terms of it, and how to control
and measure it. External meters don't work as well as a power supply
that shows current directly without a voltage drop across the meter
and jumper wires to consider. The big advantage of a lab supply is its
adjustable current limit which protects the load, and sometimes the
user.

Yeah, current limiting seems like the way to go for safety. I don't
recall seeing that feature on any of the old supplies I ever worked
with, but it's been awhile. I could have forgotten.

My favorites were made by Power Designs, and I got them for good
prices at hamfests, because I knew them from having worked with them at
work. Two styles.

2005 0-20V 0-0.5 A adjustable in steps of 1 mV. Just dial
in the desired voltage from 0-10V, and a switch adds
another 10V if you need it. It has a nice current
limit. They even have the zener reference in a crystal
oven, so the voltage does not drift with room
temperature variations. Plug them in and the ovens
starts working, and once the front panel light for
the oven starts cycling, it will be stable.

3650 0-36V, 0-5A, with a variac built in so the difference
between the voltage out of the transformer and the
voltage desired out of the front panel terminals is not
too different, so you don't have to drop too much
voltage (and thus heat in the regulator.

I got two of the 2005s in a rack-mount frame for practically
nothing. The seller said that he could not get them to work, and I
glanced at the rear panels, and found the jumper blocks where the
external sense could be wired had some wires coming from it going off to
nowhere. Just replace jumpers between the "+" and "+sense" terminals,
and likewise between the "-" and "-sense" terminals and they worked just
like they were supposed to. :-)

These are fantastic if someone else pays for them:
http://www.home.agilent.com/en/pc-85...?&cc=US&lc=eng

Or -- if you get them at a hamfest or someplace like that which
sells surplus equipment. The hams bid on a lot for something they
particularly want, and sell the rest for very little at the hamfests.

Most eBay vendors have a better idea what they are selling, and
what it is worth to someone at least. :-)

A couple o' multis, please!


and this has the capability of the 4-quadrant V-I supply that is the
heart of an automated analog semiconductor tester:
http://www.keithley.com/products/dca...rpose/?mn=2400
http://en.wikipedia.org/wiki/Automatic_test_equipment

Nice.

That would be nice. And I've liked Keithly equipment in the
past.

[ ... ]

Cheap import lab supplies are good enough for my home experimenting,
such as measuring the resistance of a motor or antenna by forcing 1
Amp through it and reading milliOhms as milliVolts. Even a $4 HF DVM
will resolve tenths of a milliOhm that way. The power supply's output
voltage can be turned down very low so an open shouldn't damage the
circuit being checked, for example the wiring harness of an old
vehicle.

Huh? How can an open harm a circuit? (Other than arcing, and its
resultant damage and chaos?)

The short which should be there is holding the voltage low. If
the open occurs, the voltage shoots up to whatever the supply is set to,
and this may be too much for something else connected to the same wires
-- or not too much, but the wrong polarity.

I used 9v batteries to check for opens and shorts in wiring harnesses
when I wrenched for the body shop. Lots of fenders were driven into
the looms when the bodies crumpled. I repaired and retaped (miles)
many a harness, since it was usually cheaper to repair than it would
be to replace it. In most instances, it was only one or two wires
which were damaged (usually severed.)

The 9V batteries are probably no problem for most things in
older cars, but there may be things in the newer ones which don't like
even that much voltage. Just like an old analog multimeter which on the
Ohms range can provide enough voltage to zap a logic chip, while a
Digital one limits the maximum voltage to perhaps 1V or so.

[ ... ]

It won't do both at once. I was looking for parts at a flea market to
complete a less ambitious one when I found the salvaged front panel,
with a 10A Variac and 40V and 20A meters, so I used the other
components I had already collected to resurrect it. It's not regulated
(yet) but good enough to quickly charge a dead battery or bench-test
heater and wiper motors that need more than the 5A limit of my lab
supplies. I don't like to connect sickly, sluggish DC motors directly
to a battery. It's safer to turn up the voltage on them slowly while
watching the current.

Aw, ya wuss!

At a recent hamfest, I got a motor-generator -- 28 VDC input,
115 VAC three phase 400 Hz output. I could not run it from the total of
the power supplies on my bench, but I recently got a dainty little
transformer from a friend -- NOS. Dual primaries for either 120 VAC or
240 VAC input, and two center-tapped secondaries, each capable of 20 A
at 12V (or at 6V using the center taps). With the two secondaries in
series I get 24VAC at 20 Amps -- and that through a bridge rectifier
and with a big filter cap runs that motor-generator nicely.

What is such an inverter used for -- to power certain aircraft
instruments, including to spin up gyros built into instruments.

I've measured the DC current or AC power most of my antique
electronics consume and written it on them for when they need work
later. Yesterday I extended the wiring to my 1950's TV antenna rotator
and then watched the power the controller drew when turned back on to
confirm I hadn't miswired it. Now I can unplug it where it comes into
the basement instead of going out in the rain when lightning is
predicted.

You live in that kind of area, eh?

Doesn't everyone? We get a lot of it during the summer. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 17 Sep 2013 04:57:44 GMT, "DoN. Nichols"
wrote:

On 2013-09-15, Larry Jaques wrote:
On Sun, 15 Sep 2013 10:12:52 -0400, "Jim Wilkins"
wrote:

[ ... ]

When I was learning the intricacies of op-amp measurement circuits OJT
I realized that voltage can just sit there but current HAS to be
accounted for, and began thinking in terms of it, and how to control
and measure it. External meters don't work as well as a power supply
that shows current directly without a voltage drop across the meter
and jumper wires to consider. The big advantage of a lab supply is its
adjustable current limit which protects the load, and sometimes the
user.

Yeah, current limiting seems like the way to go for safety. I don't
recall seeing that feature on any of the old supplies I ever worked
with, but it's been awhile. I could have forgotten.

My favorites were made by Power Designs, and I got them for good
prices at hamfests, because I knew them from having worked with them at
work. Two styles.

2005 0-20V 0-0.5 A adjustable in steps of 1 mV. Just dial
in the desired voltage from 0-10V, and a switch adds
another 10V if you need it. It has a nice current
limit. They even have the zener reference in a crystal
oven, so the voltage does not drift with room
temperature variations. Plug them in and the ovens
starts working, and once the front panel light for
the oven starts cycling, it will be stable.

3650 0-36V, 0-5A, with a variac built in so the difference
between the voltage out of the transformer and the
voltage desired out of the front panel terminals is not
too different, so you don't have to drop too much
voltage (and thus heat in the regulator.

I'll keep eyeballs peeled for those, Don. Thanks. Speaking of crystal
ovens, I have one from the '50s which I use as a fire safe. It's made
with that horrid OHMIGODWEREALLGONNADIE asbestos stuff.


I got two of the 2005s in a rack-mount frame for practically
nothing. The seller said that he could not get them to work, and I
glanced at the rear panels, and found the jumper blocks where the
external sense could be wired had some wires coming from it going off to
nowhere. Just replace jumpers between the "+" and "+sense" terminals,
and likewise between the "-" and "-sense" terminals and they worked just
like they were supposed to. :-)

I love it when I find things like that. My neighbor gave his golf
cart to me when it wouldn't charge or run. I had to replace a $5
cable between batteries and sold the thing for $900. I gave him $100
for the thing after the fact, and told him "it cost under $50 to
repair."


and this has the capability of the 4-quadrant V-I supply that is the
heart of an automated analog semiconductor tester:
http://www.keithley.com/products/dca...rpose/?mn=2400
http://en.wikipedia.org/wiki/Automatic_test_equipment

Nice.

That would be nice. And I've liked Keithly equipment in the
past.

[ ... ]

Cheap import lab supplies are good enough for my home experimenting,
such as measuring the resistance of a motor or antenna by forcing 1
Amp through it and reading milliOhms as milliVolts. Even a $4 HF DVM
will resolve tenths of a milliOhm that way. The power supply's output
voltage can be turned down very low so an open shouldn't damage the
circuit being checked, for example the wiring harness of an old
vehicle.

Huh? How can an open harm a circuit? (Other than arcing, and its
resultant damage and chaos?)

The short which should be there is holding the voltage low. If
the open occurs, the voltage shoots up to whatever the supply is set to,
and this may be too much for something else connected to the same wires
-- or not too much, but the wrong polarity.

OK, I'll almost buy that. But what happened to those components
-after- the incident but -before- the short dropped the voltage, hmm?


I used 9v batteries to check for opens and shorts in wiring harnesses
when I wrenched for the body shop. Lots of fenders were driven into
the looms when the bodies crumpled. I repaired and retaped (miles)
many a harness, since it was usually cheaper to repair than it would
be to replace it. In most instances, it was only one or two wires
which were damaged (usually severed.)

The 9V batteries are probably no problem for most things in
older cars, but there may be things in the newer ones which don't like
even that much voltage. Just like an old analog multimeter which on the
Ohms range can provide enough voltage to zap a logic chip, while a
Digital one limits the maximum voltage to perhaps 1V or so.

Yeah, I keep forgetting that I stopped wrenching before most of the
cars went to digital systems. I haven't had to troubleshoot any of
the newer ones since I've owned only brand new trucks (2) since then.
It's sure nice not having to get my fingernails dirty any more. I wish
I'd remembered to wear latex gloves during house painting this last
week, though. Oh, those new white 3mil nitrile gloves at HF are TITS,
guys. They're quite a bit like latex only they're 5 times tougher,
resistant to more solvents, and much easier to install/remove. I love
those things enough that I have a dozen in my BOB.


It won't do both at once. I was looking for parts at a flea market to
complete a less ambitious one when I found the salvaged front panel,
with a 10A Variac and 40V and 20A meters, so I used the other
components I had already collected to resurrect it. It's not regulated
(yet) but good enough to quickly charge a dead battery or bench-test
heater and wiper motors that need more than the 5A limit of my lab
supplies. I don't like to connect sickly, sluggish DC motors directly
to a battery. It's safer to turn up the voltage on them slowly while
watching the current.

Aw, ya wuss!

At a recent hamfest, I got a motor-generator -- 28 VDC input,
115 VAC three phase 400 Hz output. I could not run it from the total of
the power supplies on my bench, but I recently got a dainty little
transformer from a friend -- NOS. Dual primaries for either 120 VAC or
240 VAC input, and two center-tapped secondaries, each capable of 20 A
at 12V (or at 6V using the center taps). With the two secondaries in
series I get 24VAC at 20 Amps -- and that through a bridge rectifier
and with a big filter cap runs that motor-generator nicely.

Cool! Was your "dainty" above facetious? 20A usually isn't schmall.
Now that I own a ham radio (Baofeng UV-5R portable) I need to get my
tickee and go to those ham fests so I can find your treasures here.


What is such an inverter used for -- to power certain aircraft
instruments, including to spin up gyros built into instruments.

I've measured the DC current or AC power most of my antique
electronics consume and written it on them for when they need work
later. Yesterday I extended the wiring to my 1950's TV antenna rotator
and then watched the power the controller drew when turned back on to
confirm I hadn't miswired it. Now I can unplug it where it comes into
the basement instead of going out in the rain when lightning is
predicted.

You live in that kind of area, eh?

Doesn't everyone? We get a lot of it during the summer. :-)

AFAIK, I've never lived where lighting struck wires or antennas. It
has never affected me personally during my 60 years so far. (Me glad,
BTW)

--
Try not to become a man of success but
rather try to become a man of value.
--Albert Einstein

On 2013-09-17, Larry Jaques wrote:
On 17 Sep 2013 04:57:44 GMT, "DoN. Nichols"
wrote:

On 2013-09-15, Larry Jaques wrote:

[ ... ]

Yeah, current limiting seems like the way to go for safety. I don't
recall seeing that feature on any of the old supplies I ever worked
with, but it's been awhile. I could have forgotten.

My favorites were made by Power Designs, and I got them for good
prices at hamfests, because I knew them from having worked with them at
work. Two styles.

2005 0-20V 0-0.5 A adjustable in steps of 1 mV. Just dial
in the desired voltage from 0-10V, and a switch adds
another 10V if you need it. It has a nice current
limit. They even have the zener reference in a crystal
oven, so the voltage does not drift with room
temperature variations. Plug them in and the ovens
starts working, and once the front panel light for
the oven starts cycling, it will be stable.

3650 0-36V, 0-5A, with a variac built in so the difference
between the voltage out of the transformer and the
voltage desired out of the front panel terminals is not
too different, so you don't have to drop too much
voltage (and thus heat in the regulator.

I'll keep eyeballs peeled for those, Don. Thanks. Speaking of crystal
ovens, I have one from the '50s which I use as a fire safe. It's made
with that horrid OHMIGODWEREALLGONNADIE asbestos stuff.

Here is what my 2005s look like -- eBay auction #261287963296
including a back view showing the terminal strip where the
jumpers are -- or should be. :-) This is not the least expensive
in the auctions -- but the first with a good clear photo.

And *here*: (ebay auction #370875530364) is a newer version.

The other should be 3650-S (I went down and looked at it).
eBay auction #300756127978. To the left of center, down near
the bottom are a lamp and a knob. The knob sets the current
limit and the lamp turns on when the limit is actually limiting.
The switch to the right turns the meter from voltage to current.

The 2005 supplies have similar -- plus a button to short the
output so you can set the limit you want.

I got two of the 2005s in a rack-mount frame for practically
nothing. The seller said that he could not get them to work, and I
glanced at the rear panels, and found the jumper blocks where the
external sense could be wired had some wires coming from it going off to
nowhere. Just replace jumpers between the "+" and "+sense" terminals,
and likewise between the "-" and "-sense" terminals and they worked just
like they were supposed to. :-)

I love it when I find things like that. My neighbor gave his golf
cart to me when it wouldn't charge or run. I had to replace a $5
cable between batteries and sold the thing for $900. I gave him $100
for the thing after the fact, and told him "it cost under $50 to
repair."

:-)

[ ... ]

Huh? How can an open harm a circuit? (Other than arcing, and its
resultant damage and chaos?)

The short which should be there is holding the voltage low. If
the open occurs, the voltage shoots up to whatever the supply is set to,
and this may be too much for something else connected to the same wires
-- or not too much, but the wrong polarity.

OK, I'll almost buy that. But what happened to those components
-after- the incident but -before- the short dropped the voltage, hmm?

Who knows -- but give them the best chance, at least. :-)

[ ... ]

The 9V batteries are probably no problem for most things in
older cars, but there may be things in the newer ones which don't like
even that much voltage. Just like an old analog multimeter which on the
Ohms range can provide enough voltage to zap a logic chip, while a
Digital one limits the maximum voltage to perhaps 1V or so.

Yeah, I keep forgetting that I stopped wrenching before most of the
cars went to digital systems. I haven't had to troubleshoot any of
the newer ones since I've owned only brand new trucks (2) since then.

Most of my work on cars was back when, too. Except for a few
things on the Mazda Navajo (really a Ford SUV with a badge change. :-)
The worst was changing the radius rods, which either required tools to
compress and take apart the front suspension (which I did not have), or
removing two big heavy rivets on each side on the rails below the front
seats. A combination of drilling and an air chisel to get those off.
:-) Replaced with bolts, of course. :-)

It's sure nice not having to get my fingernails dirty any more. I wish
I'd remembered to wear latex gloves during house painting this last
week, though. Oh, those new white 3mil nitrile gloves at HF are TITS,
guys. They're quite a bit like latex only they're 5 times tougher,
resistant to more solvents, and much easier to install/remove. I love
those things enough that I have a dozen in my BOB.

I've got some blue ones from MSC, and really like them.

[ ... ]

At a recent hamfest, I got a motor-generator -- 28 VDC input,
115 VAC three phase 400 Hz output. I could not run it from the total of
the power supplies on my bench, but I recently got a dainty little
transformer from a friend -- NOS. Dual primaries for either 120 VAC or
240 VAC input, and two center-tapped secondaries, each capable of 20 A
at 12V (or at 6V using the center taps). With the two secondaries in
series I get 24VAC at 20 Amps -- and that through a bridge rectifier
and with a big filter cap runs that motor-generator nicely.

Cool! Was your "dainty" above facetious?

A mere 16 lbs -- by the step on the bathroom scale holding it,
vs not holding it approach. :-) It is the larges which I have not built
into something, though the one in the Best Power Systems UPS is bigger.
And perhaps in a couple of smaller UPS as well.

The bridge rectifier is one of the metal housing ones, and I've
got it held in a small drill press vise as a temporary heat sink, and it
does get rather warm. :-)

20A usually isn't schmall.
Now that I own a ham radio (Baofeng UV-5R portable) I need to get my
tickee and go to those ham fests so I can find your treasures here.

Well ... you need the ticket to use the transmit function of the
radio, but you don't need it to go to the hamfests. I've been going to
them for over 30 years (they've gotten smaller and fewer over that
period) and up until this year, I didn't have a license.

About three hamfests back, I won a door prize for the first time
-- a little handheld Yeasu FT250 2-meter transceiver, and decided that
the time had come. So I dove into a couple of sites giving the practice
exams to see how much I needed to learn, and after a little while at the
Technician (entry) level, I decided to try the General, and found that I
felt pretty good about that, too. I then tried the one for the Extra
class, and actually passed that (barely) the first try, so I kept diving
into that too. By the time the next local exams came up, I decided to
try for all three -- and passed all three. The Extra class was the one
which really needed my calculator quite a bit. (But, interestingly
enough, the actual exam I took did not need it -- it was pretty easy.)
In the practice, I had to refresh my memory on things like calculating
reactance at frequencies in capacitors and inductors, and calculating
resonant frequencies. Also a lot of summing resistance, inductance, and
capacitance at a given frequency (or just with the reactances given, and
figure out which of a number of labeled points on a graph it is.

Note that you can get up to 9 wrong on Technician and General
and still pass -- and up to 12 wrong on the Extra (50 questions instead
of 35). And they don't tell you what you got wrong.

My approach worked for me, since I had been an electronic
technician for a long time, and could easily spot the ridiculous answers
given (multiple-guess) and narrow things down fairly quickly, and make
pretty good guesses at some of the others, including what happens when
you combine more than one antenna in a particular way (I didn't know, but
I was able to guess a number of them.)

And then there are the "Smith Charts" -- graphical way of
solving complex reactance questions. I knew what they were for, but I
still don't know how to use them properly. I figured that I could pass
while getting *all* of those wrong. :-)

Here is one of the practice sites: http://aa9pw.com/radio/

and the other: http://www.eham.net/exams/

Both are built from the real questions used in the exams, and
each time you take one, you get a different collection of questions.

Both tell you what you got right and wrong, and what was right
if you got a question wrong. The first one tells you in order, while
the other one tells you in some sort of scrambled order.

The actual exam gave the same choices as the practice ones, but
the order of the choices (officially called "distractors") is different,
so you can't remember a question and say "That should be answer C". But
if you recognize the question and know *how* to answer it, you can spot
the right one.

The practice exams gave me the confidence to just go in, but
depends on what you already know. A lot of people I would suggest get
the books and read up and study. But take the practice exams first to
get an idea how much you need to learn.

Good Luck with your exam(s) (however many you choose to take.)
Note that to take the Extra class, you have to first take and pass
Technician and General. It does not have to be all in one day. If you
pass the earlier ones, you get a certificate which you can present when
you take later ones (they are often given at hamfests, and at other
locations.) Some places charge, others do it for free. The place I
picked turned out to be for free -- and I didn't know that until after I
had passed them all. :-) Those that charge charge per session, not per
exam, so if you take all three or just one the cost is the same.

Oh -- and if you pass one or more of the earlier ones, once you
get your license from that (less than a week in my experience), you
don't need to present the certificates. And you don't even need to wait
until you receive the license on paper -- as soon as your name and new
call sign are posted on the FCC site, you can start using the
transmitter.

FWIW -- I'm now KV4PH.

And so far, nothing with greater range than the little handheld
2-meter, which reaches from Vienna out to the Bluemont repeater (perhaps
45 miles -- but Bluemont has a *big* antenna tower on a mountain, so
that is a lot better than from handheld at ground level to another
handheld at ground level.

[ ... ]

I've measured the DC current or AC power most of my antique
electronics consume and written it on them for when they need work
later. Yesterday I extended the wiring to my 1950's TV antenna rotator
and then watched the power the controller drew when turned back on to
confirm I hadn't miswired it. Now I can unplug it where it comes into
the basement instead of going out in the rain when lightning is
predicted.

You live in that kind of area, eh?

Doesn't everyone? We get a lot of it during the summer. :-)

AFAIK, I've never lived where lighting struck wires or antennas. It
has never affected me personally during my 60 years so far. (Me glad,
BTW)

Interesting. I grew up in South Texas, and the old house had
lightning rods. And I remember them "thummm"ing when struck. And we
also had a few trees (not many in South Texas) hit and large chunks
split off. There was not much rain, but when there was, it was often a
serious thunderstorm, and I remember sitting on the porch watching it
approach -- and loved to watch it.

Here (Northern VA), lots more trees, and the ground is not as
level, so I usually can't watch a thunderstorm approach, except on the
weather radar put up by a couple of the TV stations. And while *I* don't
mind thunder, one of our cats runs under a particular solid chair at the
first sound of it. :-)

Oh yes -- and occasionally in the winter we get thunder-snow. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

rOn 17 Sep 2013 23:20:03 GMT, "DoN. Nichols"
wrote:

On 2013-09-17, Larry Jaques wrote:
On 17 Sep 2013 04:57:44 GMT, "DoN. Nichols"
wrote:

On 2013-09-15, Larry Jaques wrote:

[ ... ]

Yeah, current limiting seems like the way to go for safety. I don't
recall seeing that feature on any of the old supplies I ever worked
with, but it's been awhile. I could have forgotten.

My favorites were made by Power Designs, and I got them for good
prices at hamfests, because I knew them from having worked with them at
work. Two styles.

2005 0-20V 0-0.5 A adjustable in steps of 1 mV. Just dial
in the desired voltage from 0-10V, and a switch adds
another 10V if you need it. It has a nice current
limit. They even have the zener reference in a crystal
oven, so the voltage does not drift with room
temperature variations. Plug them in and the ovens
starts working, and once the front panel light for
the oven starts cycling, it will be stable.

3650 0-36V, 0-5A, with a variac built in so the difference
between the voltage out of the transformer and the
voltage desired out of the front panel terminals is not
too different, so you don't have to drop too much
voltage (and thus heat in the regulator.

I'll keep eyeballs peeled for those, Don. Thanks. Speaking of crystal
ovens, I have one from the '50s which I use as a fire safe. It's made
with that horrid OHMIGODWEREALLGONNADIE asbestos stuff.

Here is what my 2005s look like -- eBay auction #261287963296
including a back view showing the terminal strip where the
jumpers are -- or should be. :-) This is not the least expensive
in the auctions -- but the first with a good clear photo.

And *here*: (ebay auction #370875530364) is a newer version.

Ouch! They aren't giving those away, are they?


Yeah, I keep forgetting that I stopped wrenching before most of the
cars went to digital systems. I haven't had to troubleshoot any of
the newer ones since I've owned only brand new trucks (2) since then.

Most of my work on cars was back when, too. Except for a few
things on the Mazda Navajo (really a Ford SUV with a badge change. :-)
The worst was changing the radius rods, which either required tools to
compress and take apart the front suspension (which I did not have), or
removing two big heavy rivets on each side on the rails below the front
seats. A combination of drilling and an air chisel to get those off.
:-) Replaced with bolts, of course. :-)

Um, rivets aren't supposed to be removed, sir. g That means you
usually have to support the engine/trans, then remove the xmember and
about 400 other things to get at the item you need to replace. Lots
of fun, that.



Cool! Was your "dainty" above facetious?

A mere 16 lbs -- by the step on the bathroom scale holding it,
vs not holding it approach. :-) It is the larges which I have not built
into something, though the one in the Best Power Systems UPS is bigger.
And perhaps in a couple of smaller UPS as well.

Thot so.


The bridge rectifier is one of the metal housing ones, and I've
got it held in a small drill press vise as a temporary heat sink, and it
does get rather warm. :-)
Har!


20A usually isn't schmall.
Now that I own a ham radio (Baofeng UV-5R portable) I need to get my
tickee and go to those ham fests so I can find your treasures here.

Well ... you need the ticket to use the transmit function of the
radio, but you don't need it to go to the hamfests. I've been going to
them for over 30 years (they've gotten smaller and fewer over that
period) and up until this year, I didn't have a license.

I knew that. I was just saying that I need to go to learn stuff and
to find those treasures you found.


About three hamfests back, I won a door prize for the first time
-- a little handheld Yeasu FT250 2-meter transceiver, and decided that
the time had come.

Congrats for the old win!


So I dove into a couple of sites giving the practice
exams to see how much I needed to learn, and after a little while at the
Technician (entry) level, I decided to try the General, and found that I
felt pretty good about that, too. I then tried the one for the Extra
class, and actually passed that (barely) the first try, so I kept diving
into that too. By the time the next local exams came up, I decided to
try for all three -- and passed all three. The Extra class was the one
which really needed my calculator quite a bit. (But, interestingly
enough, the actual exam I took did not need it -- it was pretty easy.)
In the practice, I had to refresh my memory on things like calculating
reactance at frequencies in capacitors and inductors, and calculating
resonant frequencies. Also a lot of summing resistance, inductance, and
capacitance at a given frequency (or just with the reactances given, and
figure out which of a number of labeled points on a graph it is.

You went whole hog into it, dincha?


Note that you can get up to 9 wrong on Technician and General
and still pass -- and up to 12 wrong on the Extra (50 questions instead
of 35). And they don't tell you what you got wrong.

My approach worked for me, since I had been an electronic
technician for a long time, and could easily spot the ridiculous answers
given (multiple-guess) and narrow things down fairly quickly, and make
pretty good guesses at some of the others, including what happens when
you combine more than one antenna in a particular way (I didn't know, but
I was able to guess a number of them.)

I only spent 3 years as a tech and didn't really learn as much as I
would have wished. I have regrets about that, but I wasn't prepared
to drive 2-3 hours in rush hour traffic to the outskirts of Sandy Eggo
to get it.

Except for the complete lack of money while self-employed, I haven't
regretted going solo. ;-/


And then there are the "Smith Charts" -- graphical way of
solving complex reactance questions. I knew what they were for, but I
still don't know how to use them properly. I figured that I could pass
while getting *all* of those wrong. :-)

Here is one of the practice sites: http://aa9pw.com/radio/

and the other: http://www.eham.net/exams/

Both are built from the real questions used in the exams, and
each time you take one, you get a different collection of questions.

Both tell you what you got right and wrong, and what was right
if you got a question wrong. The first one tells you in order, while
the other one tells you in some sort of scrambled order.

I have a Ham CD a friend gave to me with all the exam questions and
answers, programs, and information on it, and I bought the Dummies
Guide to Ham Radio (pdf) the other day. It's just a matter of
studying them and takee tickee.


The actual exam gave the same choices as the practice ones, but
the order of the choices (officially called "distractors") is different,
so you can't remember a question and say "That should be answer C". But
if you recognize the question and know *how* to answer it, you can spot
the right one.

The practice exams gave me the confidence to just go in, but
depends on what you already know. A lot of people I would suggest get
the books and read up and study. But take the practice exams first to
get an idea how much you need to learn.

Ayup.


Good Luck with your exam(s) (however many you choose to take.)

Just the Tech, at least for now.


Note that to take the Extra class, you have to first take and pass
Technician and General. It does not have to be all in one day. If you
pass the earlier ones, you get a certificate which you can present when
you take later ones (they are often given at hamfests, and at other
locations.) Some places charge, others do it for free. The place I
picked turned out to be for free -- and I didn't know that until after I
had passed them all. :-) Those that charge charge per session, not per
exam, so if you take all three or just one the cost is the same.

Interesting.


Oh -- and if you pass one or more of the earlier ones, once you
get your license from that (less than a week in my experience), you
don't need to present the certificates. And you don't even need to wait
until you receive the license on paper -- as soon as your name and new
call sign are posted on the FCC site, you can start using the
transmitter.


FWIW -- I'm now KV4PH.

When did you get that? I think they're up to 6 digits nowadays.


And so far, nothing with greater range than the little handheld
2-meter, which reaches from Vienna out to the Bluemont repeater (perhaps
45 miles -- but Bluemont has a *big* antenna tower on a mountain, so
that is a lot better than from handheld at ground level to another
handheld at ground level.

I haven't been terribly intrigued by Ham, so I'd likely just use it as
a local emergency radio when (not if) the SHTF.


AFAIK, I've never lived where lighting struck wires or antennas. It
has never affected me personally during my 60 years so far. (Me glad,
BTW)

Interesting. I grew up in South Texas, and the old house had
lightning rods. And I remember them "thummm"ing when struck. And we
also had a few trees (not many in South Texas) hit and large chunks
split off. There was not much rain, but when there was, it was often a
serious thunderstorm, and I remember sitting on the porch watching it
approach -- and loved to watch it.

I'll bet that was fantastic, though loud as hell.


Here (Northern VA), lots more trees, and the ground is not as
level, so I usually can't watch a thunderstorm approach, except on the
weather radar put up by a couple of the TV stations. And while *I* don't
mind thunder, one of our cats runs under a particular solid chair at the
first sound of it. :-)

Oh yes -- and occasionally in the winter we get thunder-snow. :-)

That's weird. Nevahoiduvit. I find thunder and lightning
fascinating, too. AFAIK, I've never been scared of it.
Earthquakes are kinda cool, too. (Well, up to 4.5 is all I've felt.)

--
Try not to become a man of success but
rather try to become a man of value.
--Albert Einstein

On 09/17/2013 08:34 AM, Larry Jaques wrote:

Cool! Was your "dainty" above facetious? 20A usually isn't schmall.
Now that I own a ham radio (Baofeng UV-5R portable) I need to get my
tickee and go to those ham fests so I can find your treasures here.


ARRL page for hamfest search:

http://www.arrl.org/hamfests/search

Prolly one reasonably close. No tickee required.



technomaNge
--
Going to one soon, in someplace called "Satsuma".

On 2013-09-18, Larry Jaques wrote:
rOn 17 Sep 2013 23:20:03 GMT, "DoN. Nichols"
wrote:

On 2013-09-17, Larry Jaques wrote:
On 17 Sep 2013 04:57:44 GMT, "DoN. Nichols"
wrote:

[ ... ]

My favorites were made by Power Designs, and I got them for good
prices at hamfests, because I knew them from having worked with them at
work. Two styles.

2005 0-20V 0-0.5 A adjustable in steps of 1 mV. Just dial
in the desired voltage from 0-10V, and a switch adds
another 10V if you need it. It has a nice current
limit. They even have the zener reference in a crystal
oven, so the voltage does not drift with room
temperature variations. Plug them in and the ovens
starts working, and once the front panel light for
the oven starts cycling, it will be stable.

3650 0-36V, 0-5A, with a variac built in so the difference
between the voltage out of the transformer and the
voltage desired out of the front panel terminals is not
too different, so you don't have to drop too much
voltage (and thus heat in the regulator.

I'll keep eyeballs peeled for those, Don. Thanks. Speaking of crystal
ovens, I have one from the '50s which I use as a fire safe. It's made
with that horrid OHMIGODWEREALLGONNADIE asbestos stuff.

BTW -- I was meaning to ask how big a crystal oven you *have*.
A fire safe for *what*? The crystal ovens I have plug into an octal
tube socket, and have just enough room inside for the heating element,
the thermal switch, and a quartz crystal (say about 1" x 3/4" by 3/8"
depending on the age and the style). The Power Designs 2005s have a
zener diode in there instead -- same principle -- keep the temperature
steady to keep the value (frequency or voltage) steady. I do have a
larger one which could hold a medium size prescription pill bottle. It
has a glass enclosed (and likely in vacuum) crystal. Overall size is
about that of a beer can.

Here is what my 2005s look like -- eBay auction #261287963296
including a back view showing the terminal strip where the
jumpers are -- or should be. :-) This is not the least expensive
in the auctions -- but the first with a good clear photo.

And *here*: (ebay auction #370875530364) is a newer version.

Ouch! They aren't giving those away, are they?

Nope -- but they were around $500-$900 in the late 1960s. which
would be several K these days. Hamfests are better than eBay -- but you
have to wait longer to find what you want. :-)

Yeah, I keep forgetting that I stopped wrenching before most of the
cars went to digital systems. I haven't had to troubleshoot any of
the newer ones since I've owned only brand new trucks (2) since then.

Most of my work on cars was back when, too. Except for a few
things on the Mazda Navajo (really a Ford SUV with a badge change. :-)
The worst was changing the radius rods, which either required tools to
compress and take apart the front suspension (which I did not have), or
removing two big heavy rivets on each side on the rails below the front
seats. A combination of drilling and an air chisel to get those off.
:-) Replaced with bolts, of course. :-)

Um, rivets aren't supposed to be removed, sir. g That means you
usually have to support the engine/trans, then remove the xmember and
about 400 other things to get at the item you need to replace. Lots
of fun, that.

Well ... I went through several web pages about how to change
them (actually the bushings on the radius rods), and given the tools I
had, the remove the rivets and put in the bolts fit better. Just
getting a big enough socket inside the front coil spring was a nasty
job, and I did not want to put that much torque on it without having a
hydraulic lift. Jack stands are just not that steady, even with several
extras.

And some of the web pages said that they *may* have bolts
already, suggesting that either the factory used them some of the time,
and rivets the rest -- or that it was a common repair approach. :-)

It worked, which is what matters. :-)

Cool! Was your "dainty" above facetious?

A mere 16 lbs -- by the step on the bathroom scale holding it,
vs not holding it approach. :-) It is the larges which I have not built
into something, though the one in the Best Power Systems UPS is bigger.
And perhaps in a couple of smaller UPS as well.

Thot so.


The bridge rectifier is one of the metal housing ones, and I've
got it held in a small drill press vise as a temporary heat sink, and it
does get rather warm. :-)
Har!

I don't want to know how hot it would get without the drill
press vise. I really ought to put it on a proper heat sink -- if I want
to make this a permanent assembly.


I also ought to measure just how much current I'm drawing from
the thing. :-)

20A usually isn't schmall.
Now that I own a ham radio (Baofeng UV-5R portable) I need to get my
tickee and go to those ham fests so I can find your treasures here.

Well ... you need the ticket to use the transmit function of the
radio, but you don't need it to go to the hamfests. I've been going to
them for over 30 years (they've gotten smaller and fewer over that
period) and up until this year, I didn't have a license.

I knew that. I was just saying that I need to go to learn stuff and
to find those treasures you found.

Learning what you need to pass the exam(s) won't tell you what
these good things in the hamfests are. The hams who bought the lot at
the surplus sale have already pulled out the directly ham-related stuff
for their own use. :-)

I recognized these because I used to work for an Army R&D lab
(Night Vision Labs at the time), and we had *good* test and lab
equipment.

About three hamfests back, I won a door prize for the first time
-- a little handheld Yeasu FT250 2-meter transceiver, and decided that
the time had come.

Congrats for the old win!

Thanks. Just the motivation I needed to try for my license. :-)


So I dove into a couple of sites giving the practice
exams to see how much I needed to learn, and after a little while at the
Technician (entry) level, I decided to try the General, and found that I
felt pretty good about that, too. I then tried the one for the Extra
class, and actually passed that (barely) the first try, so I kept diving
into that too. By the time the next local exams came up, I decided to
try for all three -- and passed all three. The Extra class was the one
which really needed my calculator quite a bit. (But, interestingly
enough, the actual exam I took did not need it -- it was pretty easy.)
In the practice, I had to refresh my memory on things like calculating
reactance at frequencies in capacitors and inductors, and calculating
resonant frequencies. Also a lot of summing resistance, inductance, and
capacitance at a given frequency (or just with the reactances given, and
figure out which of a number of labeled points on a graph it is.

You went whole hog into it, dincha?

Well ... as I was learning about the questions in the earlier
exams, I was learning that there were things which I could not do as a
Technician which I could as a General, and things which I could not do
as a General which I could do only as an Extra, so I figured that I
should go for the highest so I would not wind up accidentally doing
something which I could only do as a higher class.

*And* -- since I retired, I normally sleep until 1:00 PM, and
stay up really late working on various things, and I had to be at the
exam site at 0900. I figured that if I could do that only *once* I
would be happier. :-)

[ ... ]

My approach worked for me, since I had been an electronic
technician for a long time, and could easily spot the ridiculous answers
given (multiple-guess) and narrow things down fairly quickly, and make
pretty good guesses at some of the others, including what happens when
you combine more than one antenna in a particular way (I didn't know, but
I was able to guess a number of them.)

I only spent 3 years as a tech and didn't really learn as much as I
would have wished. I have regrets about that, but I wasn't prepared
to drive 2-3 hours in rush hour traffic to the outskirts of Sandy Eggo
to get it.

Understood. I was driving about 45 minutes each way (going the
opposite direction of the majority of rush-hour traffic), so that was
not too bad -- until the government would pull the wintertime game of
"There's a blizzard out there, but you can't go home yet." "Still not
too bad -- stick around" (repeat several time), and then finally "No
sane man should be on the roads -- go home!" at the exact same time that
all the other government employees are sent home throughout the
Washington DC area. (DC, Southern MD, and Northern VA). This makes for
a five or six hour drive home. :-)

Except for the complete lack of money while self-employed, I haven't
regretted going solo. ;-/

Understood.

[ ... ]

Here is one of the practice sites: http://aa9pw.com/radio/

and the other: http://www.eham.net/exams/

Both are built from the real questions used in the exams, and
each time you take one, you get a different collection of questions.

Both tell you what you got right and wrong, and what was right
if you got a question wrong. The first one tells you in order, while
the other one tells you in some sort of scrambled order.

I have a Ham CD a friend gave to me with all the exam questions and
answers, programs, and information on it, and I bought the Dummies
Guide to Ham Radio (pdf) the other day. It's just a matter of
studying them and takee tickee.

How long ago did he give it to you? The exams are updated about
once every three years, with the Extra class one updated in 2011 IIRC.
So it is about time for the Technician class to be updated next year, I
think.

[ ... ]

Good Luck with your exam(s) (however many you choose to take.)

Just the Tech, at least for now.

O.K. You're more used to getting up early than I am these days. :-)

[ ... ]

FWIW -- I'm now KV4PH.

When did you get that? I think they're up to 6 digits nowadays.

I got it about mid-September this year. The "Extra Class" gets
the more desirable shorter call signs by default. (If you have a longer
one from Technician class, and later pass the General and Extra class
exams, you have the option of keeping the call you got earlier (you're
used to using it), or to go to a shorter call as you prefer. You can
also put in requests for the even shorter ones as they come available
(two years after the holder gives up his license, or dies). There is a
big scramble for those, of course. :-) So, this is one other benefit of
going for all three exams at once. I don't have to decide whether to
change calls later. :-)

And so far, nothing with greater range than the little handheld
2-meter, which reaches from Vienna out to the Bluemont repeater (perhaps
45 miles -- but Bluemont has a *big* antenna tower on a mountain, so
that is a lot better than from handheld at ground level to another
handheld at ground level.

I haven't been terribly intrigued by Ham, so I'd likely just use it as
a local emergency radio when (not if) the SHTF.

O.K. Of course, when it hits, the license will probably not be
worth the paper it is printed on. :-) But being used to using the radio,
and knowing the other people in the area will probably be a benefit.

AFAIK, I've never lived where lighting struck wires or antennas. It
has never affected me personally during my 60 years so far. (Me glad,
BTW)

BTW -- Part of the exams -- even the Technician class ones -- is
how to properly ground an antenna tower. One of the questions is about
how to run the ground wires, with one of the choices being that you make
neat right-angle bends in the wires. (That is a no-no. Same for
lightning rods -- they take a gentle curve out from the edge of the roof
and curve back to the vertical part. A sharp bend increases the
inductance, and thus a lot more voltage appears across that bend.
Smooth curves and as short as possible to each of multiple grounding rods
driven into the earth.

Interesting. I grew up in South Texas, and the old house had
lightning rods. And I remember them "thummm"ing when struck. And we
also had a few trees (not many in South Texas) hit and large chunks
split off. There was not much rain, but when there was, it was often a
serious thunderstorm, and I remember sitting on the porch watching it
approach -- and loved to watch it.

I'll bet that was fantastic, though loud as hell.

As a little kid, I loved the noise and the sight of the bolts.
I know some adults who can't stand the lighting and thunder.

[ ... ]

Oh yes -- and occasionally in the winter we get thunder-snow. :-)

That's weird. Nevahoiduvit.

Tends to happen only in certain weather conditions, usually a
blizzard in this area. It is uncommon enough so the TV weather men make
a big thing about it each time it happens. Probably about once every
three years, here.

I find thunder and lightning
fascinating, too. AFAIK, I've never been scared of it.
Earthquakes are kinda cool, too. (Well, up to 4.5 is all I've felt.)

I've only *noticed* one -- a couple of years ago towards central
Virginia. It shook a few things off shelves up here, but no damage to
the house. However, it brought the triangular brick part under the end
of a roof toppling down on a bunch of cars in the parking lot a few
miles way -- sort of variable how hard it hit.

The other I've been in, but did not notice directly, was in
Guyaquil Ecuador. I woke up and heard voices out in the street
(vendors) crying "terramoto" (earthquake), but the springing on the bed
kept me from feeling it -- though it might have helped me wake up then. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | (KV4PH) Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 18 Sep 2013 04:22:37 GMT, "DoN. Nichols"
wrote:

On 2013-09-18, Larry Jaques wrote:
rOn 17 Sep 2013 23:20:03 GMT, "DoN. Nichols"
wrote:

On 2013-09-17, Larry Jaques wrote:
On 17 Sep 2013 04:57:44 GMT, "DoN. Nichols"
wrote:

[ ... ]

My favorites were made by Power Designs, and I got them for good
prices at hamfests, because I knew them from having worked with them at
work. Two styles.

2005 0-20V 0-0.5 A adjustable in steps of 1 mV. Just dial
in the desired voltage from 0-10V, and a switch adds
another 10V if you need it. It has a nice current
limit. They even have the zener reference in a crystal
oven, so the voltage does not drift with room
temperature variations. Plug them in and the ovens
starts working, and once the front panel light for
the oven starts cycling, it will be stable.

3650 0-36V, 0-5A, with a variac built in so the difference
between the voltage out of the transformer and the
voltage desired out of the front panel terminals is not
too different, so you don't have to drop too much
voltage (and thus heat in the regulator.

I'll keep eyeballs peeled for those, Don. Thanks. Speaking of crystal
ovens, I have one from the '50s which I use as a fire safe. It's made
with that horrid OHMIGODWEREALLGONNADIE asbestos stuff.

BTW -- I was meaning to ask how big a crystal oven you *have*.
A fire safe for *what*? The crystal ovens I have plug into an octal
tube socket, and have just enough room inside for the heating element,
the thermal switch, and a quartz crystal (say about 1" x 3/4" by 3/8"
depending on the age and the style). The Power Designs 2005s have a
zener diode in there instead -- same principle -- keep the temperature
steady to keep the value (frequency or voltage) steady. I do have a
larger one which could hold a medium size prescription pill bottle. It
has a glass enclosed (and likely in vacuum) crystal. Overall size is
about that of a beer can.

Mine's a bit larger. Roughly 14d x 18w x 20"t. There's a small
padlock hasp on the side and 2 shelves in the middle. The heater was
taken out before I got it, and there is a light bulb socket outside
(lower right near the back) which let you know it was running. I put
a piece of steel over the grommeted 3/4" hole on the top.

I keep legal papers, DVD backups, and a few coins in it.


Here is what my 2005s look like -- eBay auction #261287963296
including a back view showing the terminal strip where the
jumpers are -- or should be. :-) This is not the least expensive
in the auctions -- but the first with a good clear photo.

And *here*: (ebay auction #370875530364) is a newer version.

Ouch! They aren't giving those away, are they?

Nope -- but they were around $500-$900 in the late 1960s. which
would be several K these days. Hamfests are better than eBay -- but you
have to wait longer to find what you want. :-)

I'm liking that new Chiwanese $50 p/s better already.


Yeah, I keep forgetting that I stopped wrenching before most of the
cars went to digital systems. I haven't had to troubleshoot any of
the newer ones since I've owned only brand new trucks (2) since then.

Most of my work on cars was back when, too. Except for a few
things on the Mazda Navajo (really a Ford SUV with a badge change. :-)
The worst was changing the radius rods, which either required tools to
compress and take apart the front suspension (which I did not have), or
removing two big heavy rivets on each side on the rails below the front
seats. A combination of drilling and an air chisel to get those off.
:-) Replaced with bolts, of course. :-)

Um, rivets aren't supposed to be removed, sir. g That means you
usually have to support the engine/trans, then remove the xmember and
about 400 other things to get at the item you need to replace. Lots
of fun, that.

Well ... I went through several web pages about how to change
them (actually the bushings on the radius rods), and given the tools I
had, the remove the rivets and put in the bolts fit better. Just
getting a big enough socket inside the front coil spring was a nasty
job, and I did not want to put that much torque on it without having a
hydraulic lift. Jack stands are just not that steady, even with several
extras.

That's when you borrow your buddy's lift and do it overhead, while
standing up. Much safer and easier. Shadetree's a bitch.


And some of the web pages said that they *may* have bolts
already, suggesting that either the factory used them some of the time,
and rivets the rest -- or that it was a common repair approach. :-)

It worked, which is what matters. :-)

OK, but do keep an eye on the tightness of those bolts. Or didja
locktight 'em?


Cool! Was your "dainty" above facetious?

A mere 16 lbs -- by the step on the bathroom scale holding it,
vs not holding it approach. :-) It is the larges which I have not built
into something, though the one in the Best Power Systems UPS is bigger.
And perhaps in a couple of smaller UPS as well.

Thot so.


The bridge rectifier is one of the metal housing ones, and I've
got it held in a small drill press vise as a temporary heat sink, and it
does get rather warm. :-)
Har!

I don't want to know how hot it would get without the drill
press vise. I really ought to put it on a proper heat sink -- if I want
to make this a permanent assembly.

Yeah, I'll bet.


I also ought to measure just how much current I'm drawing from
the thing. :-)

20A usually isn't schmall.
Now that I own a ham radio (Baofeng UV-5R portable) I need to get my
tickee and go to those ham fests so I can find your treasures here.

Well ... you need the ticket to use the transmit function of the
radio, but you don't need it to go to the hamfests. I've been going to
them for over 30 years (they've gotten smaller and fewer over that
period) and up until this year, I didn't have a license.

I knew that. I was just saying that I need to go to learn stuff and
to find those treasures you found.

Learning what you need to pass the exam(s) won't tell you what
these good things in the hamfests are. The hams who bought the lot at
the surplus sale have already pulled out the directly ham-related stuff
for their own use. :-)

Twice, you've seemed to miss my dual point, seeing only one in the
sentence. Should I have put it A) I need to get my tickee and B) go
to the hamfests to find treasures (and pick brains)?


I recognized these because I used to work for an Army R&D lab
(Night Vision Labs at the time), and we had *good* test and lab
equipment.

About three hamfests back, I won a door prize for the first time
-- a little handheld Yeasu FT250 2-meter transceiver, and decided that
the time had come.

Congrats for the old win!

Thanks. Just the motivation I needed to try for my license. :-)

Indeed!


So I dove into a couple of sites giving the practice
exams to see how much I needed to learn, and after a little while at the
Technician (entry) level, I decided to try the General, and found that I
felt pretty good about that, too. I then tried the one for the Extra
class, and actually passed that (barely) the first try, so I kept diving
into that too. By the time the next local exams came up, I decided to
try for all three -- and passed all three. The Extra class was the one
which really needed my calculator quite a bit. (But, interestingly
enough, the actual exam I took did not need it -- it was pretty easy.)
In the practice, I had to refresh my memory on things like calculating
reactance at frequencies in capacitors and inductors, and calculating
resonant frequencies. Also a lot of summing resistance, inductance, and
capacitance at a given frequency (or just with the reactances given, and
figure out which of a number of labeled points on a graph it is.

You went whole hog into it, dincha?

Well ... as I was learning about the questions in the earlier
exams, I was learning that there were things which I could not do as a
Technician which I could as a General, and things which I could not do
as a General which I could do only as an Extra, so I figured that I
should go for the highest so I would not wind up accidentally doing
something which I could only do as a higher class.

Grok that. I intend to keep Ham low-key, so technician class is fine
for me. If I get a wild hare later, so be it.


*And* -- since I retired, I normally sleep until 1:00 PM, and
stay up really late working on various things, and I had to be at the
exam site at 0900. I figured that if I could do that only *once* I
would be happier. :-)

[ ... ]

My approach worked for me, since I had been an electronic
technician for a long time, and could easily spot the ridiculous answers
given (multiple-guess) and narrow things down fairly quickly, and make
pretty good guesses at some of the others, including what happens when
you combine more than one antenna in a particular way (I didn't know, but
I was able to guess a number of them.)

I only spent 3 years as a tech and didn't really learn as much as I
would have wished. I have regrets about that, but I wasn't prepared
to drive 2-3 hours in rush hour traffic to the outskirts of Sandy Eggo
to get it.

Understood. I was driving about 45 minutes each way (going the
opposite direction of the majority of rush-hour traffic), so that was

I had that same opposite drive 15 minutes each way, so when SKF took
over Palomar Technology and combined entities elsewhere, I was ****ed.
I've been self-employed ever since, though.


not too bad -- until the government would pull the wintertime game of
"There's a blizzard out there, but you can't go home yet." "Still not
too bad -- stick around" (repeat several time), and then finally "No
sane man should be on the roads -- go home!" at the exact same time that
all the other government employees are sent home throughout the
Washington DC area. (DC, Southern MD, and Northern VA). This makes for
a five or six hour drive home. :-)

Except for the complete lack of money while self-employed, I haven't
regretted going solo. ;-/

Understood.

[ ... ]

Here is one of the practice sites: http://aa9pw.com/radio/

and the other: http://www.eham.net/exams/

Both are built from the real questions used in the exams, and
each time you take one, you get a different collection of questions.

Both tell you what you got right and wrong, and what was right
if you got a question wrong. The first one tells you in order, while
the other one tells you in some sort of scrambled order.

I have a Ham CD a friend gave to me with all the exam questions and
answers, programs, and information on it, and I bought the Dummies
Guide to Ham Radio (pdf) the other day. It's just a matter of
studying them and takee tickee.

How long ago did he give it to you? The exams are updated about
once every three years, with the Extra class one updated in 2011 IIRC.
So it is about time for the Technician class to be updated next year, I
think.

2012.


[ ... ]

Good Luck with your exam(s) (however many you choose to take.)

Just the Tech, at least for now.

O.K. You're more used to getting up early than I am these days. :-)

I am. I get up at 4 or 5am most days, even Sunday. g
I'm in bed reading at 7pm some days, and turn the lights out at 10ish.


[ ... ]

FWIW -- I'm now KV4PH.

When did you get that? I think they're up to 6 digits nowadays.

I got it about mid-September this year. The "Extra Class" gets
the more desirable shorter call signs by default. (If you have a longer
one from Technician class, and later pass the General and Extra class
exams, you have the option of keeping the call you got earlier (you're
used to using it), or to go to a shorter call as you prefer. You can
also put in requests for the even shorter ones as they come available
(two years after the holder gives up his license, or dies). There is a
big scramble for those, of course. :-) So, this is one other benefit of
going for all three exams at once. I don't have to decide whether to
change calls later. :-)

G


And so far, nothing with greater range than the little handheld
2-meter, which reaches from Vienna out to the Bluemont repeater (perhaps
45 miles -- but Bluemont has a *big* antenna tower on a mountain, so
that is a lot better than from handheld at ground level to another
handheld at ground level.

I haven't been terribly intrigued by Ham, so I'd likely just use it as
a local emergency radio when (not if) the SHTF.

O.K. Of course, when it hits, the license will probably not be
worth the paper it is printed on. :-) But being used to using the radio,
and knowing the other people in the area will probably be a benefit.

Perzactly.


AFAIK, I've never lived where lighting struck wires or antennas. It
has never affected me personally during my 60 years so far. (Me glad,
BTW)

BTW -- Part of the exams -- even the Technician class ones -- is
how to properly ground an antenna tower. One of the questions is about
how to run the ground wires, with one of the choices being that you make
neat right-angle bends in the wires. (That is a no-no. Same for
lightning rods -- they take a gentle curve out from the edge of the roof
and curve back to the vertical part. A sharp bend increases the
inductance, and thus a lot more voltage appears across that bend.
Smooth curves and as short as possible to each of multiple grounding rods
driven into the earth.

Interesting. I grew up in South Texas, and the old house had
lightning rods. And I remember them "thummm"ing when struck. And we
also had a few trees (not many in South Texas) hit and large chunks
split off. There was not much rain, but when there was, it was often a
serious thunderstorm, and I remember sitting on the porch watching it
approach -- and loved to watch it.

I'll bet that was fantastic, though loud as hell.

As a little kid, I loved the noise and the sight of the bolts.
I know some adults who can't stand the lighting and thunder.

Most can't. I've always been a science buff and wild stuff thrills
me. There aren't too many things more wild than lightning.


[ ... ]

Oh yes -- and occasionally in the winter we get thunder-snow. :-)

That's weird. Nevahoiduvit.

Tends to happen only in certain weather conditions, usually a
blizzard in this area. It is uncommon enough so the TV weather men make
a big thing about it each time it happens. Probably about once every
three years, here.

Kinda like Sandy Eggo weathermen going nuts over red tides and grunion
runs.


I find thunder and lightning
fascinating, too. AFAIK, I've never been scared of it.
Earthquakes are kinda cool, too. (Well, up to 4.5 is all I've felt.)

I've only *noticed* one -- a couple of years ago towards central
Virginia. It shook a few things off shelves up here, but no damage to
the house. However, it brought the triangular brick part under the end
of a roof toppling down on a bunch of cars in the parking lot a few
miles way -- sort of variable how hard it hit.

The other I've been in, but did not notice directly, was in
Guyaquil Ecuador. I woke up and heard voices out in the street
(vendors) crying "terramoto" (earthquake), but the springing on the bed
kept me from feeling it -- though it might have helped me wake up then. :-)

Dad and I were on a guys-only trip to Mexico when I woke up one
morning. I had never felt an earthquake and he asked if I'd felt the
one at 4am. I was ****ed that I'd slept through my first one. He said
it was about a 3.2 or so, nothing to write home about. I was 16, I
think.

--
Try not to become a man of success but
rather try to become a man of value.
--Albert Einstein

"DoN. Nichols" wrote in message
...
On 2013-09-17, Larry Jaques
wrote:
...
Huh? How can an open harm a circuit? (Other than arcing, and its
resultant damage and chaos?)

The short which should be there is holding the voltage low. If
the open occurs, the voltage shoots up to whatever the supply is
set to,
and this may be too much for something else connected to the same
wires
-- or not too much, but the wrong polarity.

OK, I'll almost buy that. But what happened to those components
-after- the incident but -before- the short dropped the voltage,
hmm?

Who knows -- but give them the best chance, at least. :-)

There are reverse-biased parasitic or intentional diode structures
between an IC's signal pins and its power and ground. These diodes may
not be able to handle much current.
http://www.analog.com/static/importe...09090AN109.pdf
Look at 8-24, "DIGITAL INPUT AND OUTPUT RELATED SCR STRUCTURES IN CMOS
DACS"
"Forward biasing any one of the four diodes shown in Figure 4 can lead
to [destructive] SCR action if the current through them is high
enough."

If you disconnect a car's battery and then ohm out signal wires, the
ohmmeter's voltage is higher than the car electronics' positive power
supply which is at zero volts. Current from the meter may pass through
the input protection diode into the + supply and try to power up the
device, which might then draw enough current to burn out the input. A
few milliamps from a DVM isn't so bad but the 1 Amp I suggested to
measure milliOhms is very capable of causing damage unless the power
supply voltage is set below the forward voltage of a diode.

This PS-305DM here can source 2A with the open-circuit voltage set to
100mV, which should be safe(?). The Analog Devices article warns next
to Figure 6:
The most common cause [of SCR latch-up] is when the input voltage
exceeds Vdd by about 0.3 to 0.7 volts."

jsw

"DoN. Nichols" wrote in message
...
On 2013-09-18, Larry Jaques
wrote:

Learning what you need to pass the exam(s) won't tell you what
these good things in the hamfests are. The hams who bought the lot
at
the surplus sale have already pulled out the directly ham-related
stuff
for their own use. :-)


My generator, backup Internet laptop and two of my three TV-recording
computers plus the antenna rotator came from hamfests, cheap. Not
every find is treasure, but I've found enough that worked or was
easily repairable to stay ahead.
jsw

"Larry Jaques" wrote in message
...
On 18 Sep 2013 04:22:37 GMT, "DoN. Nichols"

wrote:


Ouch! They aren't giving those away, are they?

Nope -- but they were around $500-$900 in the late 1960s. which
would be several K these days. Hamfests are better than eBay -- but
you
have to wait longer to find what you want. :-)

I'm liking that new Chiwanese $50 p/s better already.

I haven't found any problems with this locally-bought PS-305DM yet. On
the 1A range it resolves to 1mA, which is nice for testing ham-fest
surplus power components and reforming electrolytic caps. It can be
set to within 1mA, or ~20mV, with the fine adjust knobs. Between it
and the 1KV megger I'm well equipped to check out the surplus stuff I
buy for my alternative energy experiments.

One of my lab supplies, maybe the Russian switcher, wasn't too happy
measuring the resistance of a transformer winding that acted like a
large choke and confused its current regulation, but it apparently
wasn't damaged.

jsw